temps should definitely be higher that 28c mate. especially in winter if you want to continue feeding. as Shell said, 32c would be nice.
the spotteds wont eat if it's cold.
if they're still not feeding after a few days of the temps being put up, maybe think about braining the pinkies, scenting with chicken or quail, or if that doesn't work, maybe try assist feeding (or calling someone you know that has experience with this)
good luck with them.