Reliance Trends — double payment for a single purchase

Address:

Sambalpur, Odisha, 768017

I purchased stuffs of amount ₹1745 on 17 february 2017 against which paid amou through sbi debit card, amount got deducted from account which was notified to me via message but the cash counter executive said transaction was declined and i had to pay again in cash. It has been 11 days & i haven't got the refund.
When i contacted the local outlet, they are denying such happening. What to do now?
I have every proof of purchase & payment.