Don’t know what I paid for and still owe for?!! My contract expired!

Been on the phone with about 6 different people from subscriber collections to customer care back to collections etc. without anyone being able to tell me what I still owe Vodacom anothet R151 for?! I paid what my statement said was due (R378) and my account apparently is still in arrears and nobody can tell me what for? It just says ‘contract balance’ but my contract ended on 9 October 2017. I gave notice in September 2017 that I will not continue with my contract but was still billed a full R278 for that month, plus now apparently an additional R151 for the balance of contract? What balance? It ended in October 2017 and thy collected a full month on 1 November. Can somebody please let me know what this is for and close my account and remove me from your database. I will never do business with you again.