Vodacoms unprofessionalism

I was due for contract renewal in April and with much hassle and over about 20 calls back and forth with numerous agents all providing me with different options and information and thereafter proceeding to do the incorrect thing , when I only wanted to renew my contract as it was, I was told that there will be a anual fee increase In April (the same month i was renewing my contract) which I agreed upon and my total bill was R194 that included the fee increase however at the beginning of May I was charged a higher amount and again contacted the call center to which no one was able to assist and kept referring me to other people, finally after more back and forth they managed to sort the pricing issue out in June, this month I receive an invoice and statement and my fees are not the same as last month I don't even understand how it can change every month without anyone contacting me , but this is totally unacceptable, i am shocked by the incompetence of vodacom this year

I was contacted and told that I will be charged a different fee every month for VAT purposes however in my previous invoice it stated VAT included , how is it possible to charge a customer different fees every month based on a set contract , the agent there after closed my query without getting back to me, I received an sms stating that my query was attended to which it wasn't, I am actually appalled by this .