No service

I need help to cancel my contract. It is a data sim so I dont have a MTN nr to call from and cancel the contract. I had the contract for many years and in December 2023 wanted to upgrade to get a laptop. However MTN at N1 City had to order the laptop for me but January 2024 I went in and was informed that there was a laptop but it is for another customer (don't know what I am and why my order was not placed) anyway I decided to go to vodacom who had laptops in stock and I was actually prioritised as a customer.... then my struggle started to get the contract cancelled. I've sent numerous emails, but get response a week later to say please reply with your details, I reply with details and then week later response come... what the heck???????? So please can you assist me with cancelling a sim only data contract. I was also informed that notice period is 30 days so my question was when does the 30days start because I informed them early January 2024 with my first email and when this madness of responding after a week started...