Poor service on fibre account

I have a fibre contract with vodacom which I paid R649 for 25mbps. After a year or so they automatically took me to 50mbps without consulting me, obviously this comes at a higher cost. I called to cancel and they said they'd take me down to a 20mbps for about R400 which I agreed to. From then onwards, they're just billing nonsense..my next debit was R749 which I never agreed to. Now in December they debited R823....imagine. I called the call centre and they're sending me from pillar to post promising to call back...I'm still waiting. The service sucks and I wouldn't recommend it to anyone..

This isn't my first dissatisfaction with vodacom