Help with a mite problem

[corinthia]

About 2 or so months ago my little crested gecko got mites in her cage really bad. My dad bought a bottle of Mite Off made by Zoo Meds.
This is the list of what he did:
Took the little girl out of the cage
Emptied the entire cage
Washed it out with water
Let sit in the sun for a day
Sprayed the entire cage
Let the cage sit in the house till it dried
Sprayed it again

With all of the leafs and climing sticks and feeding dishes he:
But them in the dishwasher and ran it on high
Sprayed them with the Mite Off stuff
But them in the dishwasher AGAIN!
Sprayed them again

With the little Crested gecko he:
Sprayed her 3 times total and rinsed her in a little water each time (waiting a day in between each spray)
All in all he used half a 8.75 fl. oz. bottle.

Before he but her back in the tank he sprayed all of her new bark bedding as well.
It took him a good 3 days to do all of the cleaning.

My father had to do all of this because the apartment I was in would not let me have them. I have resently moved to a new location and my geckos are with me now. (I have a gargoyle and nothing is wrong in his tank)

Now about a month later she has mites again. Do you think that the spray didn't work as it should, or maybe during the move mites got in there again? I though the last one would be plausible, but my gargoyle (whos tank was right beside her's) did not get any at all.

I'm not sure what to do to get rid of them... Any help?