so my ipad was recently lost or stolen, I put my ipad on lostmode immidiately and it said it would notify me when it connects to the internet. its been about a week and nothing i never sighned out of my icloud. i went and checked again on my devices but my ipad air was no longer there at all. is their anyway to retrieve the ipad back on icloud by its serial number? i dont understand how my device could not be there anymore without me deleteing it myself.