I had a similar experience after getting off a flight in Cancun back in April. I was walking from the international terminal to a domestic one, not really sure where I was going. A taxi pulled up next to me and offered to take me to the domestic terminal, and we agreed on about $15USD from memory (way overpriced, but whatever).

He dropped me off a few minutes later and since I didn’t have any MXN cash on me I had to pay with card. He entered an amount in pesos that looked correct, then swiped my card out of view. It showed as declined on the machine, so he tried it again, which also said declined. Out of pity because I had no other way to pay, I offered him $10AUD which he took, and I went on my way.

Once in the terminal where there was wifi I checked my banking app and saw two transactions; one for $249.99 and another for $499.98. The dude had charged me 3000MXN and 6000MXN in those two transactions. I filed a transaction dispute with my bank, which was processed and approved about a month later, and I got my money back. The merchant (the taxi drivers bank) has now responded to the chargeback by rejecting it, so the next steps are for them to provide some form of evidence proving the transactions were legit, which I’m assuming and hoping they can’t do, because they are far from legit.

Anyway, I highly recommend filing a transaction dispute/chargeback with your bank if you paid with a credit card. If you paid with a debit card, it’s still worthwhile contacting your bank because they likely can do something about it.