Had multiple issues with getting rewards for Mech Arena, sent in numerous screenshots of proof and emails from Mech Arena support confirming I met the reward requirements. Waited almost 1 month for them to drop a standard "Cookie Cutter" email response.
DO NOT use these people. You will at some point be scammed for your time.
P.S- Support was more than willing to just push through a small amount of rewards for the Tutorial mission. Once they had to cough up the big rewards they ran and hid.