When making a dummy booking ( in economy ) for the route in question, after selecting the flights, it shows 2 options
Pay With Miles
Pay With Cash
The Pay with miles option shows miles required to be 15000 plus 11273 for the surcharges = 26273 plus $30.50 in tax
The Pay with cash option shows miles required to be 15000 plus $124.00 for the surcharge plus $30.50 in tax
Each of these is per person
It looks like the amount charged is correct.
At the final payment screen , how much payment did it state it was going to take?