JET Account number *** I have been receiving SMS' for non payments on my account for June and July and threats that I will be black listed

JET Account number *** I have been receiving SMS' for non payments on my account for June and July and threats that I will be black listed. Despite me sending proof of payment for June with the run around..this has still not been rectified.. the staff are *********** and unskilled and dont understand your written contents of emails..Now, again I'm been receiving SMS' for non payment for July which was done on 1st July..I called Jet collections and spoke to Denise who promised to call me back as they'll look into the matter. No call to date. I've received my statement and my payments are not reflected. To my surprise I've been charged a few collection fees which must be reversed . This is so frustrating when dealing with incompenent people. My emails to them were just going back and forth as they dont read with understanding. To make matters worse all the emails from them are nameless..so you dont know who is dealing with your query..different people are dealing with your query..Please help as I'm getting no no joy..