There are going to be 2 ways to recover your account. The first is you need to know your plarium ID associated with your account. if you have your Plarium ID then you will have to contact support and they will validate your account.
The second is if you registered your facebook account to it. This one is much simpler. Log into the game through your facebook account and all your data/mechs/weapons will load in on the new device.
Best of luck!
I have the same problem with my alt account that i can't find the password of neither in the plarium account nor in the actual google account :(
Have you contacted our Support, Pilot? All progress issues can only be handled by our agents. Here is the link for you. Good luck!