Very bad service

I have been with Vodacom for 30years plus on both contract and prepaid. The problem is they have increased my installment ast month from R320.00 to R344 .00 when I ask the guy who called me said I took a gadget or something of R500.00 and I have informed him when I took the contract I was told it's a free gift. I then requested Vodacom to come and take that gift but instead they have cancelled the contract and convert it to prepaid, I then queried cancelation because I never requested for it ,they have reinstated it. I further requested for a voice recording of the inception date of the contract last month already to this date I haven't received it. Today I received sms that they are going to debit R600.00 plus on my account and they are not responding to my emails.