So . . . Little trepidation, but I'm both getting nervous awaiting a response and I'm seriously second-guessing myself. I need input

Two month ago, I sold two juvenile males to someone with other ball pythons. So, while our keeping methods are not the same, they have the species already. My snakes have not eaten for them. Period. Their other snakes eat. The situation just isn't working out. (Unless something has changed in the last week . . . I can hope.) They asked to send the snakes back for a full refund, I responded straight away that of course that worked. So far as I can tell, they haven't gotten my messages, but we sent the check, and I included typed note in the envelope.

Everything about this particular customer says "good people" to me. Otherwise, no, I would not have sent the refund out before hearing back. I've never had a customer come back with a terrible experience before and just wanted to be prompt. . . . For the customer and the snakes both. I also don't want to be seen as a flake with horrible customer service.

I do have their number. They have mine, too. Kinda got the impression they'd rather I not call, and I believe this person to be very busy, but is there a point in time at which it's acceptable to just ring someone up?

Then I've also been worried that maybe my husbandry is really weird somehow. Talk you guys into troubleshooting?
- Almost all of my BPs are in tubs, in racks.
- My racks are Varathane-coated oak plywood ranging from ~4-7 years old (continuous use), using Sterilite 6qts for hatchies and Vision tubs for adults and larger juveniles; V-70s, and V-35s.
- Temps are 87-89 on the warm side, ~78 on the coolside/ambient. It does get cooler at certain times of year. The lowermost tubs, with adult males in them, have hotspots of 85-86.
- All temps are controlled with Herpstats.
- My humidity runs around 50-60% in the cages. I do boost a little for critters in shed.
- My racks are rather heavily constructed to hold heat, and I use Ultratherm heating strips (literally laminated, pre-wired heat tape) and pads for the larger surface area. About 1/5 - 1/4 the tub floor.
- Hatchlings get one hide box, at the back of their shoeboxes, over their heat.
- Most of my adults and juvies also have only one hide. One female has no hide, another girl has two. Adults seem to move their hides around in an intentional way, so I don't worry much about placement.
- I change water every three days or sooner, as needed.
- I feed f/t. I thaw at room temp, usually 4-6 hours. Sometimes more, sometimes less. I feed in the evening and warm the rodents under a light bulb, offering on hemostats or forceps.
- Every BP not in shed is offered a meal once a week most of the year. Fall and winter, I do give the ladies a little extra.
- I clean cages as needed.
- Most of my snakes are on paper towels, some are on aspen, one is on cypress. Paper towels are my go-to, though.
- I open every tub every day, to check.
- Each BP gets handled about twice a week. Sometimes just a few minutes for cage cleaning, sometimes several minutes or longer for photos or if someone's over. Snakes in blue, I leave alone until they shed.
- Temperament-wise, two of my BPs are habitually huffy, both male. I have a mother and daughter duo who tend to be a little runny, but calm down. A couple are noticeably confident and inquisitive. The others are nice middle of the road snakes who just kind of sit there until they get bored and start crawling around.
- The snakes are in my art studio. I'm in and out of there a lot, sometimes very late at night.

Those are the main points I can think of. What else should I look at? This doesn't seem really out in left field, but, is it?

Sorry this was kinda long. All I want is to get this right and try to minimize the odds of a bad experience like this again. What can I do that I'm not doing? What can I do better?