The Spend Limit for the above mentioned number was successfully adjusted

Every month i receive an e-mail from Telkom stating exactly the following " The Spend Limit for the above mentioned number was successfully adjusted as follows" and then at the end of the month i get an extra R10 or R20 on my account added. Why would Telkom send me these kinds of messages, if i am in possession of the mentioned phone and never made the request as mentioned below. I receive these notifications on a monthly basis and there is nothing i can do about it. I have tried to stop it at Telkom offices, but with no success. Please stop doing these limit changes on my account. I have been having problems with telkom since my very first contract and i am forever sorry that i ever moved to Telkom. I will be approaching the ombudsman for a full investigation.