Hello there I have noticed that many people are starting to run short on credits, to be honest there's a simple solution that you already know but may have neglected.
The solution is keycard battles.
50 energy for Credits on Keycard battles is a great investment (if your solely after the $$$)
Ultimately Tier 2 right now gives you 110k for 50 energy so 100 energy (almost a refill) will give you 200k credits. Don't spend your energy on normal battles trying to get credit as they give you nothing. Keycard battles is definitely the way to go.
1 refill equals 120 energy so a smart way to do it is to wait until reset. You can buy 2 energy refills for 100 gems ( 240 energy ) and that will get you a good 550,000 credits if you wait the extra mins for the last 10 energy. That's 100 gems for 550k
Please don't waste your gems on the credit bundles advertised in the store. Complete waste of time as they are charging you 595 gems just for 525k credits were you can get 550k credits for 100 gems and still have 400+ gems to buy more or use elsewhere.
This will probably get fixed by the devs soon (let's be real, we all know they want your money lol check out new GW shipment refresh update) because it renders the store offer useless so take advantage of it. It's a great additional source alongside GW and challenge.
Again please don't purchase the store credits for 595 gems. Play smart!
Can't beat POE and aren't willing to change strats to defeat him? Cry nerf lol