Probably best as ELoXL suggested is to complain incessantly, but politely. Being impolite doesn't often get you too far. Diplomacy & frequency & not letting them shake you off the phone until they find a solution & guarantee it.

BTW I think Stief left a link or direct explanation of what he did to achieve a response in a similar situation. See if you can find one of his posts under the topic of optimum.