Eratic debiting of of bank account after accounts have been paid

I have on various occations been struggling to sort things out with Telkom the service provider regarding debiting of my account. Every time I phone them there is a different excuse en 10 promises that never realize. Now when you you pay your account and think that things are sorted out, they start debiting your account in the middle of the month, after you have payed your account and emailed them proof of payment. I have proof of my email and payments if they need to see it, and an sms they sent met as proof of speaking to a consultant. Their account handeling is pathetic and unprofessional and they are giving regularly paying customers a bad name on their banking account by debiting eratically making the banks think that you are not paying your accounts. I am sick and tired of phoning and just getting a new excuse that is not true. I will never ever recommend another person to open an account with Telkom again. To me their service has been unprofessional and untruthful.