As a person who worked for PetCo for three years, in all departments and as a dog trainer, I'm going to say, no you can't change it.

1.) PetCo is a retail store that just happens to sell animals and products for animals. No matter what they say ("At PetCo, animals always come first."), profits are the number one goal.

2.) PetCo corporate has their own vet. He is the one who writes the "care sheets." What he says pretty much goes. You can write a letter all you want, but they're going to side with their vet. Also there is someone who is called the RCAC. They come into each store randomly and check on the animal care. They have a checklist that says things like "each animal enclosure has a hide", "enclosure clean of waste", and other similar things. Most of the RCAC's care about animals but are very loyal to corporate. I had huge knock down, drag out fights with my RCAC about certain things. In the three years I was there, I managed to get the stores in my district to be allowed to use reptile carpet in the leopard geckos and bearded dragons enclosures. That took 3 years! Point is, PetCo is always going to say they have a vet and they have a knowledgeable corporate staff. They don't need to hire knowledgeable retail workers.

3.) PetCo is also going to tell you that it is not cost effective to house each animal in it's own enclosure. As an ex-reptile manager in a brand new reptile store, I'm going to have to agree with them. Generally these animals are only there for a month at a time, at the most. So again, it's all about profits.

4.) As for the mites... Most of the Ball Pythons (I know in my districts at least), come from Rodent Pro. These guys sell captive hatched/imports. So yeah, there's going to be mites. That's what you get from buying from some wholesalers. Not all, but some.

For the most part, the people who work there love these animals, but are just generally uneducated. They are told to strictly follow the care sheets and in the enclosures to only use the products they sell. When I was a reptile manager at the privately owned store, I pretty much did the same thing. Only my enclosures and care sheets were done correctly. It makes things easier on everyone to run things this way. But you've got to remember, they are a retail store first. You can try to change it, but I'd save your breath. Or maybe I'm just jaded.