Allow Api integration

Actually it's a cool idea. But I was trying to cancel the subscription as we just tested it for 1 month, but it didn't work. Now I'm trying to stop them to charge me th monthly fee and to refund the months that we were trying to cancel. The only thing I'm getting as answer is, that they can't find me as their customer and they can't help me. I already send them pictures of the bank-transaction and all the amounts they charged from my bank account and they still refuse and say they can't find me as their client. So I'm feeling very bad about that and would highly recommend to think about if you want them to do something like that to you too. Be careful!