MTN POOR SERVICE

Mtn YOU ARE SO UNPROFESSIONAL. I get messages to upgrade, i do so instore and no one tells me my upgrade date is 27th, they upgrade me on the 26th and I am charged a device fee because of one day????? Besides the device fee, my billing is messed up, i get charged for the old contract and new,.i am billed a huge amount for December!!! I call 135 the consultants agree with me, but the case keeps getting closed and no proper feedback. MTN I AM REALLY CONSIDERING MOVING MY ENTIRE PORTFOLIO AWAY FROM YOU