British Airways complaint: Not Allowed To fly

my Name is Touseef Mumtaz; My Cousin booked a flight via his credit card on my behalf on 19-02-2021..(cheapoair)
Booking Ref: 70433986
Air line ation : RW4ZYP
From ISB to LHR – YYZ (Toronto)

Flight No. 260
Aircraft 777 Boeing
Date: 21-02-2021
Time: 08:55 am
Ticket Cost: 785.99 USD

when I check in the boarding supervisor said that show the credit card from which payment has been made.
I said payment was made by my cousin from USA an he is also on line with me at that time.

after long discussion they suspended my ticket and show me that your payment is suspended by cheapoair( Agent).

my cousin called to agent; Agent said that British Airways withdrew all funds against this Ticket. so they must be issue Boarding card.

But supervisor simply said that you can’t board due to this.

flight was late till 11:00am; but supervisor not entertain me and i missed my flight due to British Airways.

I have to reach Canada before 22-02-2021.

i have paid 486.88 CAD extra for hotel quarantine and meal exp of 61CAD.

I Have purchased new ticket for RS 99285 (Qatar airways) and travelled to Canada on 22-2-21

you are requested to Refund BA ticket Price and Hotel and Meal exp incurred due to British airways fault.