Bumble bee nest
I do not know anything about the possible bee keepers or pest control companies in your area, but I doubt you will find anybody that regularly does that sort of thing.
Bumble bees are very docile compared to other bees, so they might be able to peacefully co-exist with you in your garage. Their colonies are not perennial, everybody but the new queens will die off in the fall. New queens will leave the nesting space to hibernate elsewhere. So, once you get to the late fall, you could seal up the entrance to whatever space they are using and make it unavailable to future bees.
I'm glad you were able to find some help that did not involve killing the bees.