[offsky]

Based on all the comments here, Im confident this is Zipcar's fault and not the OP. However, I have had some experience being on the other end of this type of billing problem (not at zipcar) so I'll share my experience.

Several times I have received an email from someone saying that my website charged their card incorrectly. In each case the amount charged has been an amount that is impossible based on what I sell (my product is $10, but they are billed for $17.23). I attempt to lookup the transaction in my Stripe dashboard using the date, amount, and last 4 digits. Nothing. I have to reply with something similar to what OP got back from support. In every case where I received a followup with the customer, they had misread the credit card statement and it was for a totally different company's charge. I guess there was a company with a similar name. Sometimes customers get quite irate, but they never apologize when they realize it was their fault.