Stop sending me messages

I paid my account and I have sent the proof of payment to cell c email three times and I'm still getting messages about not paying, I called customer service and that didn't help cause they say I must send proof of payment - WHICH I DID!!! One of the messages says that they will debit my account on the 30th of this month!!!! I will be beyond ****ed if that happens when I have already paid!!! I also would like the calls from customer service to stop because when I answer it's a machine that tells me to hold then it drops itself. This is annoying and frustrating!!!! I don't understand what's the point of sending proof of payment to an email that clearly is never checked!!!!