HELP! e280 v1 can't delete files or reformat

Like the title says, it’s a Sansa e280 (01.02.18A firmware, in MSC mode) that doesn’t actually let you delete any files from it. It looks like it deletes them, but as soon as you disconnect it from the computer, it reboots and all the songs are still there; plug it back into the computer, and all of the files you thought you deleted are right back again. (You can even copy OTHER files into the space you thought you freed up with all the songs you deleted, and it’ll do it without complaint…but like some kind of black magic, as soon as you disconnect the e280 and it reboots, those files you just copied will be gone and the old songs will be restored!)

(It’s not an MTS/MSC thing, by the way: no files were ever added in MTS mode, and just to make sure, I switched it into MTS and loaded up WMP for the very first time. It found no songs on the e280, as expected.)

Reformatting doesn’t work; it gets to 99% then dumps out with an “Unable to complete format” message. It won’t work through Disk Management, either. Even going into Recovery Mode and putting a “sansa.fmt” file in the 16MB recovery partition will get it to claim it’s reformatting…but it doesn’t actually reformat the drive, because all the files are still there.

What’s my next step? Is there something else I should be trying?

That sounds like a hardware failure.