Cheating pensioners once again!

Dear Vodacom - in the past you also ******* my mom - a pensioner to take out a new contract. Now you did it again!!! Towards the end of last year I spoke - on my mom's behalf - to someone who kept calling her, stating that she pays too much for her contract and has to change because it will be cheaper etc etc. We agreed - only to find out now that nothing was changed but only a new number / contract was added to the existing one! Shame on you and those agents. I am utterly disgusted. Until this day the contract or number has NEVER been used. On the invoice it states ***. Last time you rectified it and even explained to me that call centre agents may not call pensioners and now you did it again!!!! How do we fix this?