Bad Service

I received a high Telkom bill only to call into accounts to find out my fibre line speed was increased without my knowledge or approval, when enquired as to how to dispute this the agent says she cannot help me i need to call into sales to downgrade my services first, cannot get through to their sales department as they are experiencing high call volumes. I dont understand if yo need to log a dispute on your accounts you cant do so my bill is over double and the lack of help from accounts department is pathetic!!!!