I had exactly the same problem a year ago from HKG-LAX. I was sitting in 4A. What was your seat? After takeoff, I was horrified to find the seat wouldn't recline at all. In fact, it was in that slightly forward position you mentioned!

They gave me $250 in duty free coupons on the flight which I felt was an insult.

I wrote to Customer Service in HKG. They said the $250 was all I was getting.

I then wrote to the CEO, returning their lousy $250 coupons and said I felt really mistreated.

Customer service apologized and gave me 70,000 miles, which is good for a round trip upgrade from J to F. I thought this was fair.

I am a Diamond member. I don't know if this helped but being a Diamond member really doesn't count for much from my experience.

They should really do something for you. Since you are not a CX member, they can't give you miles but they can give you some free future upgrade certificates.
Let us know how your situation turns out.