Cathay Pacific Asia Miles - Missing MX Credit: One Way Credited, Not the Other

I had a roundtrip four weeks ago, where the outbound JFK-MEX-EZE has been credited to Asia Miles, but not the return EZE-MEX-JFK. I can't seem to find the return the tickets, but I was clearly on the return flight...what are my options at this point?

You need to find the Boarding Passes otherwise you aren't going to get the miles.

well, i was in a dbl miles promo in Nikko Ginza (Tokyo) but there isn't any proof, nor did i need to register for anything... I'm wonder if there is a way I could go and claim the double miles? not even in the confirmation email states the promotion. I've got the basic miles, but not the extra. Is there anything I could do? Should I contact AM or the hotel?

Thanks...