The 702 area code does not have a 602 telephone exchange. (702) 602-xxxx is invalid. Number is spoofed. Do not answer (block) any numbers from 702 area with a 602 exchange.
The 702 area code does have a 602 prefix. It's been assigned as of 12/22/2014 for the Jean area. The 602 prefix is owned by "Wide Voice, LLC NV" More than likely a spam number, though.