BILLING ERROR /POOR CUSTOMER SERVICE

Bought a cellphone from TFG.

I paid my last installment to them on the 3rd of May 2016, we have sent a mail asking for the insurance to be cancelled this was however never done. Now 2 years down the line I'm getting sms after sms and phone calls telling me to pay.

I have lodged this complaint with their customer service multiple times over with no success or feedback.

The last supervisor i spoke to sent me confirmation of the complaints sent to insurance department. This was done in November and there after nothing, I have emailed the above mentioned supervisor asking him if there is any feedback on this case as none of the contact numbers on his email is working.

Now the collection department is harassing me for payment after I have stated multiple times that we we are waiting for an outcome of the complaint.

How can i be held responsible for something i have paid up more than 2 years ago and because of their lack in administration they want me to pay again. This account was dormant since 2016.