Vodacom poor service

I have had a contract with Vodacom for more than 10 years, for the past 3 months Vodacom has cancelled my debit order and suspended my service, without any communication. When I realized that the debit order didn't go through I made a full payment and sent numerous emails requesting a reason why they cancelled my debit order. I had to phone them to reconnect the service, even though I was not in arrears. Needless to say no response received from them.