Why did you block my number so that I can't call the call centre???

Bathong Vodacom, are you for real??? You solve the payment allocation issue that I complained about on this platform the other day, then you block my number so that I can't call your call centre. You claim that "you detected a high call volume from my number and you have blocked it to prevent *****!" Is this a joke??? How am I supposed to cancel the contract if I can't call your call centre? I had to drive to Vodaworld just for a consultant to call the call centre in order to process the cancellation. I could have done that in the comfort of my home had you not blocked my number. I made sure I go there today, because wow!!! The blocking was enough to convince me that I needed to cancel the contract and end my relationship. Your service has been terrible to say the least. You don't even deserve the 1* rating! And by the way, I know for sure that my query was only resolved speedily because I wrote a review on this platform. Is this how you treat a customer who has had a contract with you for more than 20 years!!!! If you are able to, can you please send me a formal contract cancellation letter. Unfortunately I cannot call to request this very important document as I am blocked. I hope that I am not asking for too much. It is the least you can do considering the trouble I have gone through to cancel this contract.