Charleston wedding planner Robert Lawson Smith swore Friday to fight a Miami couple’s accusations that he defrauded them, insisting he is the victim of false allegations that have harmed his reputation and threatened his business.

“It’s scaring the hell out of me right now,” he said.

Charleston police on Sunday arrested Smith, 35, of Barre Street, and charged him with financial transaction card theft. He is accused of funneling some $28,000 that had been intended for one couple’s wedding to vendors to whom he owed money.

According to Smith, who also operates under the name “Lawson Roberts,” Wendy and Adam Shearer signed a contract authorizing him to spend $63,000 on their May 2011 ceremony.

Smith said that he consulted with the couple on choosing vendors and all the charges incurred came from vendors who provided services for their wedding.

Smith acknowledged that on some occasions he negotiated cheaper deals with vendors he had standing relationships with. Rather than charge the couple the lesser fee, Smith said he kept the difference. He said the practice is “the industry standard” in the wedding planning business, and that nothing in the disgruntled couple’s contract prohibited him from doing so.

“We’re in the business to make markups. That’s how we pay our bills,” Smith said.

The Shearers disagreed with Smith’s interpretation of their contract, however, and said they only agreed that Smith would be paid a $2,500 retainer fee and 15 percent of the total cost of the wedding.

“Nothing was misunderstood when we signed the contract,” Adam Shearer said. “We never agreed to be up-charged by thousands. He has no invoices for the charges that went to our wedding. He can’t produce any of that. The cops don’t go and arrest somebody because you misunderstood the contract.”

Wendy Shearer said Smith showed the couple one photographer’s portfolio and charged them $2,500 for that person’s services. Instead, she said, Smith paid someone else $700 to do the job and attributed the work to the original photographer.

She said she and her husband also paid Smith more than $4,000 for a band from Atlanta to perform at their reception. But, according to Shearer, Smith hired local musicians who received $1,800 to attend.

Smith denied misleading the couple and said they got everything they paid for. He also insisted he has paperwork to document the decisions made during the planning process and the expenditures that were made.

Smith said he thought everything went fine with the Shearer wedding. He provided The Post and Courier with a thank-you note he received from the couple as defense against their accusations.

“We had the wedding of our dreams cause of your expertise,” Adam Shearer stated on May 15 in an email to Smith. “People have still been texting and calling us today on how classy our wedding was. Again, thank you.”

The Shearers acknowledged the note, but explained that they sent it before they received calls from their credit card companies alerting them to possible fraud.

Wendy Shearer said Smith told them that their wedding was paid-in-full two months before the ceremony, held at a Charleston plantation.

The day before their honeymoon, however, the couple discovered up to $28,000 in charges on their credit cards for vendors that Smith had claimed to have already paid, a police incident report states.

According to the couple, Smith signed their signatures and used their cards to pay vendors unrelated to their wedding — some of which Smith owed money to before they agreed to do business with him.

The couple’s credit card companies reversed each payment the couple made to Smith, following an investigation.

Smith said that decision essentially left him with the couple’s wedding bill.

Smith pleaded his case to American Express and Visa in an attempt to get his money back, and insisted that every charge made with the Shearers’ cards went toward their wedding. They had signed an authorization form allowing him to make the charges in question on their cards, he said.

He said his problems stemmed from a change of policy at American Express that required the card holder to sign off on each individual purchase. He said he was unaware of that change and this episode was an expensive “lesson learned” in dealing with credit card companies.

Smith said American Express ultimately sided with him in finding that no fraud occurred. As proof, he provided an email from an American Express official that stated “we are not handling this as a fraud claim.”

He said the email, dated Oct. 24, 2011, was the last correspondence he had with the company on the matter.

The Shearers, however, said the credit card companies investigated Smith’s actions over the course of seven months. They said American Express’ final decision was not in Smith’s favor. They said that have emails supporting that position but they did not want to release those messages without checking with police first.

American Express officials did not return a phone call and email on Friday.

Smith said he feels Charleston police did not adequately investigate the allegations, and he feels comfortable that the criminal accusations against him will be dismissed. He also said he plans to pursue the case further in civil court.

“We are actively pursuing justice. We’re not asking for anything except the fact that they need to pay for their wedding. Call me crazy, but I don’t think that’s an unreasonable request. Services rendered, services paid for,” Smith said.

Charleston police Sgt. Donald Daquigan, who investigated the case, could not be reached for comment Friday.

Smith was previously arrested on bad check charges in November 2006, March 2009 and April 2012, but those charges were later dismissed, court records show. He said the charges stemmed “from my company being unhappy with a vendor and stopping payment.”