State Bank Of India [SBI] — Refund initiated by Myntra but did not reflect in my SBI bank account even after 12-13days

I returned two products to Myntra on 17th October and that same day Myntra initiated the refund to my source account which is SBI. But even after 12days, the amount of Rs393 and Rs424 is not showing in my bank account. When i contacted Myntra they provided me two reference numbers (ARN No. :[protected] & ARN No. :[protected]. They said that they have successfully completed the refund from their end and asked me to contact my home branch bank which is SBI Panbazaar, Guwahati. I did visit the bank but i didn't receive any help. I am worried why it is taking so much time for the money to reflect in my account.