Claiming China Eastern miles with DL

I have been DL elite plus for the past 3 years. I frequently fly on China Eastern now that I live in China. Over the past two years I have many flights that I have provided my DL number and it was printed on the boarding pass, went into the lounge etc, then the miles never show up on my DL account. I have contacted DL about the missing miles many times and faxed over all the required docs to prove I was on the flight. I have provided the boarding pass showing my DL number, the itinerary from the travel agent (showing class fare), and for some of the itineraries I have even provided the actual receipt showing the ticket cost and method of payment. These were all the things I was asked to provide, but in the end the miles have still not been added to my account.

Any ideas on how to handle this? I'm basically at the point where considering the service I get from UA and Cathay there is not much reason to even deal with DL anymore. And in addition I have tried to contact China Eastern on this matter, its practically impossible to book a seat or special meal let alone get attention from them on this type of issue.

Any feedback is appreciated!