Transfer of money

I need hello Peter to help me and my sister. My sister and I together with some ladies have a savings society and the society banks our money with u bank Welkom branch in Free State. My problem with U bank is now our savings have to be transferred to our banks and my sister is told that she won't get her money if she doesn't open an account with U bank, as she banks with Absa. Can I please get help and clarity as I really don't understand what kind of a bank is that. That can not transfer peoples money to different banks if asked to. My sister's account number was provided to the bank but they don't want to transfer the savings money to the account because it's not theirs. We don't want to open an account with U bank as we don't see a need to do so if that account won't be used on regular basis. We already have our accounts with different banks we are just asking for u bank to transfer our savings to our prospective account.