Half my contract cancelled, the rest still active

in May we cancelled our facilities Tel: *** / ***. the number *** was ported, and the hunting facilities were cancelled. but.....not all of them were, and I still get the rental invoices monthly. The amount of times I have called this in and the been passed from one person to another, and eventually the phone gets slammed down on me. Im not an unreasonable person, and I just want them to cancel it properly, but on one is willing to assist me with this. I have emailed them the request on a letterhead and everything, but still I have to pay unnecessarily. Please please help me with this.<br> <br>