Just for your information, here are the codes, but if it was represented to you as a first class ticket, said first class on the ticket, regardless of the technical category, you should sue!!
The codes in short:
F = Full-Fare First Class
P = First Class
A = First Class Discounted
R = First Class Suites (currently only
Airbus A380
"n" after any class code indicates Night Service
Business class codes
C, J = Full-fare Business Class,
D, I, Z = Business Class Discounted
Economy class codes
Full fare: Y, B
Standard fare: M, H, N
Special or discount fares: G, K, L, O, Q, R, S, T, U, V, W, X
I'd sue!