Jet
Double charging a bank account

My brother bought a phone at jet store last week saturday and then after leaving the store he realise they have charged his account twice because of the bank notification. He immediately return to the store to respond and he is told they refund but if he doesnt get the money he must come back with a bank statement which he has to bpay from his pocket. He took the bank statement either way on wednesdat but still no money and when he returns to the store after two days he is told its not done and when the cashier calls the responsible person in store he is told the lady doesnt wana see him cause she has no help for him. Am worried n strwssed caz my brother is doing an internship so he doesnt earn muxh and he needs the money for transport to work. Kindly help this is not fair at well