I will offend many with this post, but hear me out.

Laziness is the rule of thumb b'cos their jobs are almost guaranteed till retirement. As a Malaysian ex-pat living in the US, I can only generalize that MH's back office staff is almost always inefficient back in my home country. The last time I looked back into the job market there (2004), the unwritten reverse affirmative action policy is still observed for preferred hiring of Bumiputra (native Muslims, not M'sians born of other ethnic groups).

With that in mind, their systems are still relying on paper ticketing and on tons of manual audits (hence, they can hire tons of cheap staff to push paper). I've been trying to purchase tickets on MH's website but their systems keep giving me errors. For the past 4 weeks, I've been trying with phone calls to their help desk for assistance. Now, I've resorted to help of relatives living in KUL to physically purchase my tickets.

Getting back to mileage on WP, you should send documentation to NW's service desk (fax preferred). That way, you still have the original boarding passes and receipt if you still need it for MH.