HDFC Bank — HDFC Bank HDFC Bank void sales refund not received

Address:

meerut

My customer made a payment to my (on merchant's POS machine). The amount was wrong so me voided the transaction within few minutes. The amount was deducted from customer's account. But money has not been refunded.
My customer's account is with SBI and the merchant’s account is with HDFC Bank.
I am attaching the copy of voided transaction receipt.
It has been more than 3 weeks, please look into this matter.