Customer Service and Billing Query

I have been trying to contact MTN call center for a few days now and keep getting a message that they are experiencing high call volumes and they dont answer their calls. This is indictative of either very poor service resulting in customer complaints which they cannot handle or short of staff to reduce their costs. In any event very frustrating dealing with MTN. Today i held on for over 15 minutes with music blaring in my ears.<br> I had an upgrade recently and opted not to choose their itemised billing as from this month. I have just received my April statement and MTN conveniently raised a charge for itemised billing, yet my contract clearly excluded this option. I request them to reverse the charge and and to remove this fee from their billing system and confirm.