Unauthorized Cellphone Contract

I got my new monthly statement from Telkom and with that, the shock of my life. Instead of paying R487 I am now billed R882. According to Telkom I have a new contract which was activated on the 28th of Feb 2022. I did not take out a new contract, Telkom has no proof (voice recording/ signed contract) of any transaction between myself and them. Now they are excepting me to go to a Police station to get a Affidavit. They refuse to correct their mistake and are threatening to deduct this money from my account. TELKOM you need to correct this immediately. the number for the contract I am referring to is ***.