United Bank Of India [UBI] — Refund not credited back to my account

I am Sudip Ranjan Maiti, a customer o[censored]nited Bank of India having account no.[protected]. I have bought a watch on 17 Jan 2021 on flipkart of ₹5030/-. I have returned the watch to flipkart and they have refunded my money back on 15th Feb 2021. But the amount doesn't credited to my account .when I contact the customer service they told me refund already issued on 15th Feb 2021 and they provide me a reference number 74332741048104798914070 and told me to contact bank customer service. Kindly refund my money and credit it to my account as early as possible.