The Junkyard Tycoon is an offline game, so no data is stored online, we can not get back the old data. We have started the online backup Project. If you had Diamonds in your lost company, send Diamond Order ID's to Junkyard Tycoon Supoort Team, to get them back for your new company. Visit support.junkyardtycoon.com to contact Support Team. Again, we are really sorry about the issue. Keep your eye on Junkyard Tycoon social media channels and website for patch notes.
Have a great day!