Kingdiamond if the company is jacking you around so much why don't you quit now while you're ahead. Just go to you local Blockbuster rent some movies, burn'em and return them. Oh wait, you won't do that since it will cost 5 times as much. So it sounds to me like you're not getting jacked around at all, but getting a pretty sweet deal. You also might want to think about what short, long and very long wait actually mean. They are not absolute definitions of time, they are more like probabilty estimates that a particular movie will be shipped to you. If you want to increase your chances of getting those long wait movies put them in the top of your queue and the short wait in the bottom, pretty simple. However I would rather you just cancel your membership and go to NFLX where you can abuse their system. Bottom line if someone is renting dozens of movies a month they are either very cheap (like you seem to be) or a shut in that needs to go outside and look at the sun every now and then.
As a side note it's only a matter of time before everyone in this business starts putting caveats in the contract restricting the number of DVDs per month. It's just no one wants to be the first to do it.