I think they have their own crew
Occasionally, at the parts house, I run into guys who work on those big super size store. I am not sure ... but I beleive big store have in-house maintenance crew.
You might go to their web site, go to "contact Us" ask them if they are taking bit for maintenance contract.
Decide what you want, decide what you are willing to exchange for it. Establish your priorities and go to work." H.L. Hunt
"In order that people may be happy in their work, these three things are needed: They must be fit for it. They must not do too much of it. And they must have a sense of success in it." John uskin