Poor Service Delivery

I upgraded my phone (again, being an MTN customer for over 15 years already!) and this would be the first time I've received such poor service. The phone had an out of box failure and was returned to the vendor for replacement - this was done on the 11th of May, 2015 (Over 3 weeks ago!) and the response from Corporate Call Centre is 'we are working on it'. Besides the fact that nobody cares to respond to an email or call you back when you leave a message, the feedback is pathetic. Think it's time to move to another service provider as MTN obviously does not care to keep a loyal customer on their books.