Horrible service!!!

I upgraded my device on a promotion that was running in the February 2015 issue and the device comes with a free cover. The consultant told me i would receive the cover in a couple of days upon receiving my device (and not that they may be out of stock). 3 weeks later I haven't received anything. I have been calling everyday to follow up and keep being told the matter is being escalated to the supervises who are never around when i call and ask for them. I am being told contradicting stories from the consultants and when i try to get the correct information from the supervisors, they are either off or i just missed them. I logged a complaint on the website and was told i would be contacted regarding the situation and nothing has happened. The service has been appalling and i am livid! I have been a loyal customer for years, i pay my accounts on time and NEVER have i experienced such poor service from a 'respectable' company like MTN. I was told to expect a call today from the supervisor but i ended up having to call and was told to try again tomorrow!