iPod classic spazzing

I have an iPod classic that was sent to Apple to get a new battery. After a little while it began to freeze up while being used and had to be reset. When it's turned off, sometimes the screen begins to flash and it spazzes. We've restored and resynced it several times...once it would not sync but a few songs and kept giving error messages, but after several attempts it began to sync again. Now, on a daily basis, it spazzes and flashes more often. The only way to reset it is to put it on the Bose speaker dock...more recently it will not even do this. The last time it happened it crashed and erased everything on the iPod. Any ideas? The nearest Apple store is 2 hours away.