Bata India — Coupon code provided by Bata doesnt work

Hi,
I received a coupon code from Bata just before my birthday on 7th Feb. Hence I logged in my account and try to place an order online on 7th Feb and tried to use the coupon code shared by Bata, however it didnt work hence I called the customer care and shared the screenshot over email to in-customer.[protected]@bata.com about the coupon not working. Customer care over phone told me to wait for 3 days to get it resolved.
I waited for 3 days however neither I received an email nor any call for the resolution. I kept on sending reminder emails and also gave them calls however every time customer care provided me the same answer that the backend team says coupon is working and when I tried while on call with customer care it didnt work. Again I was asked over the call by the customer care to send the screenshot which I sent and they asked me to wait for 2 days.
Still not receiving any call or email from Bata I called them up again and surprisingly the customer representative told me that back end team confirmed that the coupon was used on 9th Jan. I asked the customer care person how is that possible, even he was shocked to hear that if Bata shared the coupon code with me just before my birthday date how can I use it on 9th Jan. He again escalated to the backend team and again I waited for no resolution.
Over the period of 12 days from 7th Feb to 18th Feb I had sent 10 emails to which I received no response, I called them 10 times and still no resolution provided.

Also meanwhile the Item which I was purchasing on 7th Feb was for price 699 and recently the price got increased to 746. Had there been no technical issue from Bata side I could have purchased the item on 7th Feb for 699. Why should I pay more for the same item because of issue from Bata end?

Hence resolution I am expecting is a valid coupon code and also the same item which I was purchasing on 7th Feb for 699 I need the same item for the same price.