MakeMyTrip India — Incorrect payment for currency exchange

I ordered 220 GBP from book my forex and I paid 21156 INR online accroding to the exchange rate on that day. When they delivered me the GBP notes they mentioned they dont have 20 GBP bills and offered me either 200 GBP or 250 GBP. I opted for 200 GBP which amounted to 19256 INR. I tried to contact the customer care multiple times but no response. I have all their recipets during the delivery which sates 200 GBP delivered and I also have my transaction details which shows I paid for 220 GBP.

Order ref no: FX[protected]

Date of online payment and order: 5 Sep 2022

Date of delivery: 8 Sep 2022