over charge my account wrongly.

Sir , I complaint to Vodacom about over charging my account 31/12/1014. <br> They respond to look into the matter and come back to me within 48 hours.<br> Up to now they did not come back to me and also did not rectify the problem.<br> Instead they demand a further R1355.19 from me or my phone will be suspended.<br> My sel no is *** and the problem is on the account no *** which should be R99.00 p/m.<br> for a 2 G bundle which ask me R4101.13 .... R7731.78 , R2598.16 and R6814.68 respectifly for aR99.00 top up contract.<br> Can you please assist.