Complaint on an unresolved complaint

Can Vodacom please resolve my issue? they responded after my 28th Sept review, saying they'll get in touch soon and they still haven't. when I call their call centre, the calls gets dropped or cut and they don't get back to me. I've tried 4 times just this morning. They claim I'm in arreas for R8752 but their own statements have never reflected that and by their own admission they have no idea why i was invoiced R8200(made up of 4 invoices of R2200 odd) in one month and yet they have no inclination to investigate but i keep getting sms that my query has been closed off. they don't take customer service seriously because even their feedback survey is biased. the call gets cut when the rating is not to their liking. I'm being sent from pillar to post. Does it really take almost 4 months???meanwhile this is costing me my credit record and score.