These things really are tough.... I had them bad as well, and had to chop everything and hit the reset button... Having said that... the best advice i can offer is to be on top of it with your spray routine. If you know the broad mite is a problem in your area, you should spray a minimum of once a week, if you get lazy/miss leaves while spraying or let it go longer than 7 days you're playing with fire.
IF you know you have a heavy infestation, you need to spray Nuke em 2-3 times in a 48 hour window.... broad mites reproduce much faster than most.