Payment issues

I had to change from debit order payments to EFT payments a while ago. I do get my statements via email which I then promptly pay. Around two weeks later I get a call from the Collections Department for nonpayment. Yesterday 10-July again. The operator, Keale, then confirmed that payment was made in June (although she phoned because of nonpayment!) and would "escalate" the issue and get back to me today. This morning I got an SMS stating that my account is overdue and an immediate payment is required to maintain service, THIS HAS BEEN GOING ON FOR MONTHS! I have 5x contracts with Cell-C and have been a customer for years! I will now rather go to another service provider!!