Mods/Admins do not normally give refunds on rollbacks except for credit based buys at the cs.
As to the lost levels, levels are quite easy to gain/regain in Minecraft (something I heard a mod say to someone who requested a similar refund a while back). As to the lost diamonds/sticks used to make the picks, they're where you found them. So if you mined those diamonds during the time of the roll back, they're still there. If they were in your chest, they're still there. If you bought them via credits, you need to contact the owner of whatever shop you went to. If it is the cs store, then a mod would need to go back into the logs and verify the transaction. Otherwise you won't be seeing a refund, I'm sorry to say. I also wish we could get such refunds, however one reason of logic is that doing so would create too much work on mods/admins. Sometimes, a rollback happens after a roll back, too, so it would then me 2-3 times the work.