I usually wait at least a week before feeding or handling. You said you got him Saturday, fed him Monday, and are trying to get him out to handle him already? It's no wonder he's being defensive. Also, you don't really want to handle them very much for at least a day (preferably two days) after eating because the stress may cause them to regurge.

I know it's tough to not handle a new pet, but have a little patience. Balls can live up to 50 years so you'll have plenty of time. I would suggest handling him after a couple of weeks for a few minutes a day when he's not digesting or shedding. He'll get less defensive the more comfortable and older he gets.

Oh, and spending most of his time in his hide during the day is a good sign. Balls are nocturnal and will usually spend most of the day sleeping, but you should see him wake up once the sun goes down.