Terrible service what do you expect from MTN

How do I start this conversation. I phone on the 17th of aughust 2022 to cancel my contract the cancelation advisor did not tell me that you this works on a full 30 day notice period so the your contract will end on the 10th of september and we will charge you the full amount for september. How is this not theft so you are charging me a full amount for a 3rd of the use. So I phone to get some clarity on this and spoke to a manager with the name of Riley and them I explained to him that if I was infromed that this is a 30 day notice I and I will be billed for the month none the less I would have cancelled my contract on the 1st that just makes sense. This is the worst service that I have ever recieved when Riley said he will put me trough to the complaints department and then put the phone down. Leaving me to phone again and try and sort out this theft of a cancelled contract and *****ing my money.