Poor customer service

On 30th August I was contacted by Mtn retentions department telling me that they found the phone I was looking for. I agreed to have them courier it to me. They claimed that it would take 3-7 working days and I kept calling to see how much longer it would take as it was taking extremely long. On the 8th working day after spending over 4 hours on numerous calls to find out where the phone was the *********** people at retentions department tell me they now have no stock at their warehouse. I then say to them maybe it would be easier if I get the phone myself from a store because I am tired of waiting. I called 7 of their stores around Johannesburg only to be told nobody has any stock available. I have left numerous messages on their twitter page as well as sending numerous direct messages on twitter for someone to please calll me and help me sort the problem and have received no response from anyone not even an acknowledgement of the numerous messages I have sent.