Taking money from people account.

Hi have a account with rain. December the 15th Rain deducted R3500 for from my card. My card was linked to my brothers account after I helped him with one payment 9months ago. They refuse to give my money back. The rooter or sim was not used in 9 months. When we joined rain it was said that when you dont pay a month there is no wifi so i dont understand how R3500 can be for wifi it was cut of it makes no sense. My husband past away 4 months ago leaving me to raise a daughter all by myself. I am not employed full time and is on contract. I need to give notice as i dont have the rent money and the landlord dont want to hear any excuse. My account is always paid with rain. I think that they are *****'s. I tried asking to speak to a senior and was told they dont have one :( :( I am going to take this further.