A vendor was arrested at Sunday's Miami Dolphins game after he allegedly charged a fan $724 for two beers.

Nathaniel Collier, 33, was arrested at Hard Rock Stadium in Miami for allegedly using a personal credit card reader — not the device the stadium provides to vendors — to charge the fan for the two beers, Miami-Dade police said. Authorities seized the Square reader when Collier was arrested. Collier had worked as a walking vendor at the stadium for a year, police said.

Nathaniel Collier is accused of charging a fan $724 for two beers at a Miami Dolphin's football game. Miami-Dade Police Department

Shortly after the transaction was processed, the customer received an alert on his phone from his bank notifying him of the charge to his card, according to police.

Collier worked for Rocket Man, a Kentucky-based subcontractor that employs walking vendors at major sporting events and concerts. He was fired following his arrest, the company said in a statement.

“As the chosen provider of walking vendors across dozens of stadiums, we take the matter of security extremely seriously, and train and monitor our vendors to safeguard our customers," a spokesman told NBC News. "Our onsite supervisor contacted the authorities immediately upon learning of the overcharge on what was Mr. Collier’s unauthorized personal device."

The customer received a full refund, the spokesman said.

Collier faces charges of third-degree grand theft and possession of a skimming device. He was booked into the Turner Guilford Knight Correctional Center and issued a $10,000 bond.