Very Annoyed

I have been with vodacom for so many years and they still manage to disappoint me I downgraded my phone package to save costs...i paid up my contract and wanted to move to a lower monthly package which was done on 29 June 2021 I was advised that the change would apply after i accepted as the lady still phoned back to ask if they assisted me to change etc. Fast forward a month later i get an sms from TOBI the bot saying my bill for this month is R367. This made me very blady angry, i changed because i needed to cut monthly expenses where i could. I was NOT informed that the change would only be implemented from the end of this month until i called to query this amount. All they could say was sorry that no one informed me!! . Do you pay my bills? is sorry going to pay the account for me!? I am not one bit happy with this **** really i had it with vodacom really.