Poor billing

I need somebody to please assist with: Correct my billing date Correct the billing amount

Cell c keep on deducting the incorrect amount and also on different times if month.

Please refund last month R115 that FNB took from me, after my account was paid duo to date.

And they again subtract the wrong amount en did April, but jy account had no arrears. Now my Sim is blocked again, but they were in the wrong