Still no action after numerous complaints in 2014

they messed up my contract saying they cant find conversation where I called in to ask not to continue my expiring contract, now im being billed for a sim card I had stopped using. I now got a threatening letter.<br> can some on high up who can effectively resolve customer complaints, I have also referred this matter to the consumer ombudsman, I am sick and tired of this query that I HAVE BEEN QUERYING SINCE 2014 WITH NO SUCCESS EXCEPT AN *********** PERSON WHO WAS ASSIGNED TO DEAL WITH MY ISSUE