Unknown account with Telkom

Telkom mobile has been pursuing money for an account number I didn't apply for the past eighteen months although I've sent them an affidavit from the police station, my bank statement to highlight the disputed amount and a copy of my ID which they have instructed me to submit before they can attend to my complaint. The amount was R647. 57 at the time in March 2019. However, in September they have been sending final letters of demand for R2143. 25 for the same account. Their call center is unhelpful, they have asked me to submit emails with above mentioned documents without a single response accept letters of final demand.