Vishal Mega Mart — V - Mart Valasaravakkam store - Calim amount 2050

Address: V-Mart, Valasaravakkam, Chennai - 600087

I purchased two merchandise from the store on 06/06/2022 and I went for the exchange of the same on 12/06/2022 and just requested them to add the claim value in the total bill of ₹6091 for the merchandise I purchased on 12/06/2022 which they refused and they said the terms and conditions won't allow as it is in promotion.
But my point here is, am not adding any other brand but the same brand and I don't see even a penny of loss for the company with this regards but they refused to do even after asking and explaining the issue for hours.
Along with this, particular persons there were very rude and sarcastic, claiming they are the top persons there and not disclosing their name when asked, abruptly disconnecting the call.
When I tried to raise the complainant over V-Mart customer care, they say they only process online store complaints but not offline store and I have to visit the store again for the same.
But this is ridiculous as my complaint itself is about the people in the store and I can't complaint the same to them as they claim there is no one else to contact other than them.
I am stuck in a nowhere to go situation and a loss of ₹2050 for my valuable time and energy waste.
I want justice here and want my money back along with compensation for disrespecting the customer
Hope this forum will help me!