CANNOT TRUST TELKOM OR THEIR STAFF???

My phone was ****** out of my car one morning before I went to work. I directly went to Telkom in Centurion mall (next to Pick-n-pay) and reported that my phone was ****** and that I needed a new phone. TK assisted me (he was very nice and friendly), I asked for the old insurance to be cancelled (as the phone was ******) and took insurance on the new device. The first month, they deducted two devices (cancelled and new device), then the second month it happened again. I queried this, which they rep**** it was never cancelled, and I said but I requested the insurance to be cancelled whilst in store, then they asked me if I had proof!!!? How must I prove that the person that helped me was telling the truth or lying!? So now you can't even trust a person working for Telkom, you need evidence and / or a witness? What if TK did do everything, but the system did not update, is that then not Telkom's issue and not the end user. I have now paid 3 months that I shouldn't have because according to Telkom, even the word of their own staff cannot be trusted. This is unacceptable!!!!