Dealing with thick people

I have made a small payment into my BET profile. I have sent the proof of payment as a PDF format, with the ref number to show. The stuff there is useless, they keep telling it is in the word format. I have made payment before and emailed the same proof of payment and was assisted , today they do not want to help, they keep lying say i sent a word doc. I wish I could reverse the transaction and use more reliable site. this is ****.