TNT Tacos and Tequila

The server gave himself a $16 tip on my card without my consent.
On 2/11/2020 I went to tacos and tequila with a friend. We were there about 2 hours. The service was terrible. Our server was Brayan. At the end of the right I decided not to tip due to service. My total was $86.60. Tacos and tequila does not charge automatic gratuity. Gratuity is at the discretion of the customer. On 02/11/2020. I signed my bill for $86.60 with $0 gratuity. On 02/12/2020 I noticed I had a$102.60 charge on my card from tacos and tequila which was $16 more than I paid. I called tacos and tequila and spoke to a manager. The manager looked up my receipt and said there was $16 for gratuity. I began to tell the manager I did not leave any gratuity and the server must have wrote that on there. I asked for a return of the $16 which he did not want to do. I was a victim of fraud from this company with no remorse. Charging someone's card without their consent for your own personal gain is a crime. The server had no right to steal $16 from me. If the service was better I would had left a tip. The server was name Brayan. Brayan only checked on us once in 2 hours. The manager said they charge gratuity on large group but this was not a large group and the gratuity on the receipt was clearly optional.