United Bank Of India [UBI] — Amazon refund is not credited my account

Address:	741139
Website:	www.ubi.com

Sir,
I am sukhen das, a customer of your bank, branch dhubulia. My savings account number is[protected].
I get a refund worth value ₹-6999 from Amazon of which the refund reference number is [protected].The amount should reflect in my account by[protected]. But till now it is not credited to my account.
I have called your customer care number more than hundred times and become failure every time due to line congestion. Then I visited your branch and your officials didn't help me because of their ignorance regarding this matter.
Right now I want to solve this matter wih your kind help.