What happened customer service??????!!!!?

I logged a call in store for a consultant to give me a call back, Cause I'm unable to get hold of the billing department over the phone and wait for over 40 minutes on the line, I eventually got a call back yesterday after 2 days I told the consultant to give me a call back during my lunch at 12pm yesterday she calls me at 8am yesterday during my shift I still haven't received a call back! WHAT IS HAPPENING HERE???!!!??? FIRST YOU OVER CHARGE ME AND DON'T CREDIT ME BACK AS PROMISED THEN PROMISED A CALL BACK TO SORT OUT MY BILL AND CREDITS I'M STILL WAITING!!!! SO BASICALLY I'M KINDA PAYING 2 MONTHS ON ADVANCE EVERY SINGLE MONTH!!???? Pathetic!!!!