Fbb — Billing Issue - Exchange issue - FBB Karnal

Hi Team,
First of all Thanks for opening the FBB Store at Karnal location with huge variety and great experience of shopping.
But i faced the issue regarding the billing and exchange issue at FBB, Dyal Singh colony, Kunjpura Road, Karnal - 132001, Haryana, Date of billing 12/082021 with Invoice No - [protected] and date of exchange 13/08/21.
They have issued the exchange value of voucher Rs. 1061.75 instead Rs. 1, 147 for 3 articles - for reference I have attached the exchange details and invoice.
The major issue is as per the billing executive that he told me. if i bought 3 articles at 1061.75 then in exchange you need to pay 1, 147 now. That thing is not acceptable. because if i pay the amount 1, 147 then there is no sense to make payment with HDFC Credit card and then paying back it in exchange form to FBB again.
So, I have taken the credit note of those articles and exchange items and got billed with another number with [protected] of amount 4242 with the same card details. They also did not apply the discount on HDFC Card on that billing.
The billing guy told me as an example that if i buy one article at Rs. 462 at discounted price then in exchange you need to pay Rs. 499 for the same article.
Means - Buying Value - 462 and for the same article i need to pay 499 in exchange. 37 extra while exchanging the same article. That is not justifying the buying from FBB.
Looking for a strong reply otherwise i need to return all the items and want a refund against all articles.