If you have less than 24 hours of (in game) /playtime you can #open-a-ticket in the Discord and get it back, but if your playtime is greater than 24 hours, your claim block will only be given back if the cause of death was a glitch, flew into a barrier block (not 100% guaranteed) or anything of the like.
If you don’t understand the Ticket system yet, it is explained lower down in the FAQs.