Pond5 are losing market share at an alarming rate.

Out of interest, who are they losing the market share to?

I just wanted to check if anyone else got this email? Alongside video I also sell some original sound effects on Pond5. A few months ago I went through their retroactive ID upload verification hoops and it was fine. Today I get an email asking me to email(!) them a copy of my passport again, specifically to verify my identity as a creator of sound effects(?).
Seems weird so I thought I'd ask around.

I recently decided to deactivate everything I had on Dreamstime (poor performance, low rates). I asked them by email to pay out the remainder of my account (about $65). They told me that they wont pay my royalties unless there is $100 in the account (this is in their T&Cs). I explained that I had deactivated all my files, and asked how they expected the amount to increase when I was no longer selling files. I was told to join their affiliate program (!)

Is there any recourse I can now take? If not, let this be a warning to others.
You have to wonder how much of our money they pocket this way.