Poor Service Delivery: Vodacom

am doing business with Vodacom for more than 12 years now, and currently have five contracts. Two of them I took out in February this year. Just two months later the monthly invoices of four of the contracts, including the two newest, increased. I questioned this on the 8th, 12th and again on the 19th of April, and got the following sms:

"Hi. We're sorry you didn't get your April price change update due to a technical issue on our side - both your April and May increases are on us! From 1 June 2022 there'll be a price change to your plan, view it here: https://bit.ly/3M4JFGy. T&Cs apply. Further together, Vodacom".

And the following per email; "From 1 June 2022, your MBB plan increase will be 3%."

I rep**** several times, requesting an explanation as to why four of my accounts increased in April already. I contacted Vodacom Accounts telephonically on 28 April, and Kabilo promised me the situation would be rectified. She also could not clarify a credit in the sum of R16.99.

I contacted the office of the Ceo of Vodacom via email on 05 May after a local branch also could not assisted. Dowrey?called me on 06 May, and after telling me that there are different types of contracts, she promised to investigate and email me back. After another mail on 09 May to the same office, I still did not received any feedback. Ref. No.***

Surely this is not the type of service one expects from such a big company. Especially in the current negative economy where one would expect businesses to at least try to be more customer friendly and supportive. Or must I accept that Vodacom is getting too big for their loyal customers, and does not care about service delivery?