MWEB *****s from their customers

I have migrated my ADSL line from Telkom to Mweb a few months ago. Not long after that I was a victim of this **** for the first time. 1. I pay R899 instead of R769 for uncapped premium 4MB line. Then when you don't expect it they downgrade your service to the 2MB speed without modifying your account. Now they make you overpay by R390. If they manage to cheat 1000 people per month they ***** R390,000. If you complain they simply point the finger to Telkom and Telkom point the finger back. I have now been a victim again for a second time. This time round I managed to get MWEB to admit they downgraded line speed and they do not know by whom, and why I am paying higher amount. Why is my line downgraded in the first place. I did not agree to this.