EMPTY PROMISE

I wrote and complaint about my sim card not working for months in February on the 16th ,one of your consultant called me and promised that i will get a new sim card ,actually they will deliver it for me up until today i haven't received anything, but i have to pay MTN every month for something that is not working . Can you please tell me what is this called??Are you taking advantage of us your costumers? Or you just don't care because you getting your money every month, Can you please give me a new sim card otherwise i will stop paying , you can sent me to credit bureau i don't care anymore am fed-up with you because i can't pay for something that am not using and am tired being on your back ,surely you should have picked that up that my SIM CARD is not receiving any calls nor making any calls ,but if I wasn't paying you were gonna suspend my lines because that's what MTN is good at ,can you please sort this out because its being 8months now otherwise \ CANCEL\" my contract with you because i deserve fairness this is my hard earned money ,i don't want be on your back ANYMORE PLEASE!!"