Shell

On May 5th we were trying to fill up our rental truck on the way too the airport we stopped at the shell at 1733 Parkway in Sevierville. My husband put our bank card in at the pump, it wasn't working so my husband went inside the clerk told him no issues with pump so we moved truck up and tried a different pump well this pay at the pump didn't work either so we left and went across the street where we were successful in getting gas. once we got home I noticed 2 charges for gas on May 5th. I called my bank and told them the one for shell in the amount of 70.64 is not legit as the pay at the pump wasn't working. They told me since it was done at the pump I need to call Shell to get my money back. I called and the lady said the station is independently owned so I need to contact them. out of the 15 times ive called the same guy answers the phone when I ask to speak to the manager he says "no here" or he tells me to call at a certain time and I do and same answer No Here. I am sick and tired of calling this station and I just want our money back. You allowed this guy to have a station under your company and I have done all I can to contact them. Please, please tell me what I can do to get my money back from your company.