Hi and Welcome. My Name is XXXXX XXXXX I look forward to assisting you today with your question.
Did you setup iCloud
on it ? This usually happens if there is any problem with iCloud syncing. I've had the same problem with my iPhone
and had to disable Contacts syncing.
On your iPad, goto Settings and tap iCloud. In there, if the Contacts is turned on, turn it off. Then select "Keep on My iPad" option from the resulting menu.
From now on, your contacts will not be deleted. Let me know if happens again...
About restoring, did you synced your iPad with your iTunes prior to this problem ? Or do you have backup on iCloud ?
You can check whether if you have any backup on iCloud by going to Settings > iCloud > Storage & Backup
In there, click Manage Storage and can you see your iPad's backup in there ?
Please let me know, so we can try to restore them.