billed again for a wrong contract and closed it.

I am so so furious now for the third time cellc is doing this to me. they debited money from my account for a contract they said was wrongly billed and apologised to me for it. my 3G stick is the issue here, i received a phone call from their head office to say that they have fixed the contract and cancelled that wrong package and put me on a new package that would have started working on the 1st of february 2015, and everything that was wrongly billed from me would be credited. now i find out that they have cancelled the account, debited another amount of R644.01 on the 16th february 2015 instead of the amount that we agreed upon. they cancelled my contract of thye very same 3G stick without informing me, and billed me fir what?i dont receive any statements from cellc or anything what so ever. i am very very angry at this company for being such a loyal client for years and be treated like dirt by them, after they promised me that they will fix this, FOR THE THIRD TIME IN A ROW....CELLC PLEASE FIX YOUR MESS, OR LET ME WALK TO ANOTHER NETWORK THAT WILL VALUE MY SERVICES AND THE MONEY I BRING TO THEM, AND THEY WON'T LIE TO ME 3 TIMES LIKE YOU DID.