Forced into an upgrade

I was called by their agent two weeks ago for an upgrade. <br> Our call got cut off before i could agree to the terms and conditions.<br> However after the call got cut off i received sms's stating that i was successfully upgraded.<br> I called them back and explained what had transpired and that i do not want to be upgraded.<br> I told them that they must not send me the Samsung A7, i was told that the courier would be reversed.<br> After a few days i called in and was told that the phone had been successfully returned to them.<br> I then informed them that it seems as if my contract package has been amended and i want them to restore it to its original S4 package. <br> For two weeks no one is able to assist me they keep transferring me from one department to another. Please help. I am being ********ly placed on the package of the phone i didn't consent to.