Continued Bad Service

Well, two weeks down the line I am still waiting for my replacement phone. MTN is shrugging their shoulders and stating that they are not receiving feedback from the Warehouse. When asked to escalate the matter, I was told that the Supervisor, Kelvin, is on leave so there is nobody to intervene. Even Mickey Mouse companies have a second in charge who takes over if the Manager is on leave. Any corporate firm would have made a plan e.g. stock swop with a vendor to retain the customer, but no its too much work. So if the Supervisor is on leave for three weeks or transfers to another department etc and interviews for a replacement need to be done, there is still nobody to intervene and the customer is left hanging? Seriously