Debited twice

These people don't bother to reply emails. I have sent several emails but they don't respond at all ...I made an eft to pay off my existing loan using the " pay now " option from the website. .okay fine the transaction was successful...On the same day the debit order went through..meaning what? I repaid the loan twice .I asked for a refund they don't reply me ..like they don't bother to reply emails and im getting frustrated...just pay me back my money u cant take twice the money