Jos Alukkas Kumbakonam — Concern Regarding Restriction on UPI Payment from Another Bank Account

Today, I visited Alukkas to purchase jewellery. We informed the staff that we would be making the payment through GPay/UPI.
My concern is that I was told that the payment must be made only from the bank account that I had previously submitted/registered with Alukkas. I was informed that payment from another bank account would not be accepted.
I understand that the account details may have been submitted earlier for documentation purposes. However, I would like to understand why I cannot make the payment from another bank account belonging to me through my own GPay/UPI.
Sometimes, the required amount may not be available in one particular bank account, while it may be available in another account. In such a situation, restricting the customer to one specific account creates an unnecessary difficulty.
My concern is about the payment restriction and the reason behind this policy. If the payment is being made through a valid UPI transaction, I would like to know why payment from another account is not accepted.
Therefore, I request the Head Office to kindly look into this matter, clarify the official policy, and explain the reason for imposing such a restriction on customers.
I am raising this complaint because I believe customers should be given reasonable flexibility in making legitimate payments from their own bank accounts.