Providing unrequested products without consent

I got a contract with MTN for iPhone16 pro last year November, every month the bill increases with a specific amount and it keeps on increasing, this month from 1.8k including insurance to approximately 2.8k. When I asked they are telling me about subscriptions I never accepted , even worse they say the amount is from the additional limit spend. I never ran out of data nor minutes, and I never requested any additional product besides an iPhone, I feel ****med honestly. Sadly when I ask how much is the limit given to me, nobody knows, how do you give me a product that I never requested and not know how much the limit is. My frustrations reached another level and I even consider to cancel this contract.