double debit order

vodacom double debited my bank account on 1st January 2016 at midnight. I had sufficient money in the account to pay the debit order. Now my account is in the minus. I want my money back. this is unacceptable from a company I have been doing business for more than 5 years. I have a bank statement to prove this. and Vodacom , do not tell me you won't debit me at end of January. this is not accepted. I want my money back that you took from me by double debiting.