BAD SERVICE!!!!!!

I took a cellphone contract with Telkom in 2017 which was R639 a month, to my surprise Telkom has been debiting R885.00 ever since I took the contract with them, I called them numerous times to rectify the issue but all I get is excuses after excuses. I get no assistance from the call centre even if I ask to be transferred to a line manager. I am so frustrated as to why did I even take a contract with Telkom, its the call centre agents don't even know what they are talking about, it just shows the unprofessionalism of the agents, everyone I speak to takes me from pillar to post. Its been 5 months of complaining with no help.