Service...what service?

Firstly, I upgraded nearly 2 years ago, to date I have never received an invoice. About 2 months ago I app**** for a credit card, I got a notice that I do not qualify because of my credit rating, got my credit rating and Vodacom put me on ITC for the amount of R1200. Sent vodacom an email to enquire about the amount and why I was blacklisted. It nearly took a month before they contacted me to say that I owe them money. Asked the person who phoned me to please email me the invoices so that I can see what the amount was for, he informed me that he could only send me a statement and that I needed to phone customer care. I then phoned customer care and requested the invoices, I expressly said invoices and not a statement. I received a statement which showed my account for December was R1920.00. Still don't know why its so high as the sim card is in a plastic container in the pantry, not even in a phone, and I only have a voluntary R50 additional credit on that contract sim for emergencies, my contract is below R500 each month but I pay R500 every month. Very nice of Vodacom to first blacklist you before attempting to contact you. Once again Vodacom contacted me and said that they are going to cut off my service and hand me over to the lawyers, told them that they can go ahead as I will not pay until I received the invoices requested. The lady then informed me that she could only send me the statement (very useful information) and that I needed to phone customer care for the invoices. Round and round like a goldfish in a bowl...