Contract of deceased mom

My name is Tumi Tsatsi and I am a student with UNISA and my mom had a contract on my behalf and she passed away in August. I reported that to vodacom and requested if the contract could be transfered to my name but they claimed it's not possible because I'm not employed yet. I then requested for the number to be on prepaid and I got an sms stating that I have to pay R770 for me to keep the number or else it will be removed from the network. Isn't it this things have insurance incase a person is decease the account will be written off and be on a zero balance. Why am I supposed to pay such an amount just to keep a preapid number? I'm not happy at all. But if that's the case I will never use vodacom services again and would not even encourage anyone to use it whatsoever. As we speak my number is suspended and I can make outgoing calls. Being the whole two weeks.