telkom cresta

I existed Telkom store at cresta on the 25th April to cancel my phone insurance ,I was told i needed to send an email cancellation to *** which i did and sadly i did not recieve and acknowledgement response for my request. I them returned to the store for a follow up on the 11th may and i was given a different email to use *** and still no one responded to my requests. I received an email on thr 27th of june from mutual and federal old mutual informing me of changes and new amendments regarding my police and thats where i got their new information of which i them called in and i was informed that there where no email from me regarding cancellations. I then asked for cancellation and was instructed to do so in writting. On the 9 of july my contract was cancelled. However Iam now complaining that my account is in arreas since june /july of wich i cant understand how that should be my problem when Telkom failed to do the cancellation as i have been sendind instruction to do so.I have all the emails trails for instructions i have be sending.now iam getting threats for being handed over by nudebt an amount of R945.66.. This is affecting my credit score badly and honestly someone must assist me with this urgently.I get harrased with calls from debt collector and its really disturbing my health too.