Cant level up

I have accidently deleted app which I eas playing as a guest for 4 yrs. I have lost all gains, equipment and levels. I have loaded new the character via google and cant level up because in the last necron campaign needed pass wich costs 100.000 credits! In this tempo I will colect 100.000 c in 5 yrs! Back in the days it was unlocked and needed to pass the main quest to open next campaign. Is it BUYING the only way?!?! If it is the only way it sucks amd it kills the gameing in the game!