Re: Unfair Blitz Challenges
The game does want to make money. It's not an old C&C titles where you laid out $50 and were done with it.
To get stronger units takes either time or money. I'll assume you're not spending. So find a good guild, donate units for credits - and get the units you use most. Start using what crystals you get to rush crates once it costs ~5-7 to do so. This is still the most efficient way to get resources. And do your dailies advance your units and work up towards level 60 (which is sweet in every way).
Finally watch the C&C tv - watch a few Tib level games - get some strats and deck ideas. If you cared enough to write this on the forums then you care enough to spend 10-15 minutes watching some games. I keep giving this advice - it works - I just don't think people are doing it.