Vodacom Ignoring My Requests and robbing me!

In this difficult time, Vodacom decided to bill me more than R2500 a month (for three months), after upgrading and signing a R899 contract. After the first month that I got this unpleasant surprise, I requested (have proof) feedback as to why, and to be credited for that amount and that it can not hallen again amd to be stopped. Second month sames full story, third month, same full story. Requesting many times why this is happening, why it has not been attended to, or stopped, or why I habe not been credited / refunded. Very sad, as I am a Vodacom custormer for more than 15 years, but now I am being ******. Hope Vodacom can contact me, to get this sorted as I don't want to be a client anymore as well!!