Mr price mobile sim card ****. ****med me to pay for something i did not ask for nor told off. they are refusing to refund my money

i opened an account at Mr Price and i made it clear that i do not want to pay any extra services for my card i just want to pay my monthly installments and my interest charge only to find out that they have been charging me R50 for sim card they did not even tell me about. so all this time i am paying R50 for a service that i was not even using. when i saw my statement for the 1st time because i never cared to look before and i asked the lady helping at Mr price they said the money is gone and i will not get it back. total of R250 now. this is ****, they should've told me about the airtime but they had me paying for nothing because this is how they **** people. everyone go at Mr price to check your statement, you might be paying for something you never asked for or told about.