Nashua Mobile
Over-billing

I have been ridiculously charged over a thousand rand for each of the past three months now whilst I am supposed to be debited;
R200 airtime
R59 BIS
R130 Hard drive subsidy
R149 data (modem)
Total = R538

But for the past three months I have been debited;
R1 300.77 (30-11-13)
R1 039.97 (31-12-13)
R1 067.84 (31-01-14)

I called Nashua mobile to enquire about the over-billing and was told its because of the call limit they set for me which is R 455.99. I was not happy to hear that and I requested them to change my mtn data to fixed amount of R149 for 2 gig per month and they promised to do that but nothing have been done. I am fed up now and I want to cancel my contract with Nashua mobile, I have been trying to call them all day but did not go through, even the branch is not answering the phone.