Cell c

I dont understand ..it is now the 3rd month that cell c takes R500 more from my account ..i went there last month and they told me they had a problem with the deductions.. during the month i got a sms unforming me that the correct deduction will be made ...but no ibdication on my oayback of R500 for 2 months . I thought it is sorted ..but ....alas this month again .. R 500 more ... What are they doing ??? why do we have *********** people working in places where figures are involved . My personal opinion they are *****ing my money ... It is now R1500 that they took from me and i can guarentee you i will not get it back ... Nooooo cell c after being a customer since 2005 ... ??? I want to stop my contract .. i want to warn every person against cell c.. i am a pensioner living in a budget .. R 500 is alit of money .. give my money back !!!!!