Was double charged for a Box office movie but the call center agencies can't seem to resolve my querie

I'm so disappointed with this company, I rented a movie for 35 but they decided to double charge me, I've been calling their call center speaking to different agencies non of them could help me, added to speak to their supervisor but I was on hold for almost an hour. I'm so hurt with the service I received, they can see that I was double charged but the other lady paid I must bring proof, which I fail to understand because everything it shows on the system but they choose to put me on hold. Please I need to know who can help me