Mix telematics - the worst

You guys are the absolute worst! I sold my car, i told you you guys, gave notice, only to find out i supposedly have a 24 month contract, which i wasnt even aware of. Then i paid the amount you wanted, asked for a paid up letter....nothing, its a month later, no communication,....surprise surprise i just received anothwer statement with a balance owing, this after i paid the full amount you wanted!!!! And you have me listed on the my credit bureau!!!! Really,.... no customer service...utterly poor communication....