Marathon Oil review: Unauthorized "pending" charge

I was at our local Marathon station on Placida Rd, Englewood ,FL to gas up. While my husband put my debit card in the machine and start pumping gas, I happened to go on my bank app and saw a pending $100 charge when my husband hadn't even completed the pumping. I went immediately into the building and the man behind the counter was so sketchy as I was trying to explain what was happening. He just acted stupid and kept saying "I don't know" so I ran outside and told my husband to stop and finish. It was only $30 which is my usual amount. After about 5 minutes I went back on my bank app and showed it had cleared and the correct charge was there. I feel that I was being scammed by the person working there and if I didn't run in there I would have been. I will never go back there again and will tell my friends and family not to go there ever.