STOP PHONING AND READ YOUR EMAILS

After telling them my account was sorted with Cell C as it was a mistake they could not allocate a payment and i was not behind they still phone me. I was told by Cell c not to answer their calls but they phone up to 9 times a day. I've sent my settlement letter to them but they still phone non stop. This is getting really annoying now I'm about to change my number just to get them to stop.