MBD phones you just to bill you, even if you pay

I pay MBD monthly payments towards my ABSA account. Although I pay my account, MBD has contacted me exactly 9 times since last Friday (5 working days) to remind me to pay this month again. When I queried whether I am being billed for all these harassing calls, I was answered in the affirmative. In other words, MBD phones you as many times as possible, even if you pay, just so that they can load your account with the costs of these calls. In my opinion this is very ********* practice and definitely borders on harassment. If this continues, I am definitely going to report them to the Ombutsman,