I am not even sure how websites get's listed both on BestChange and similar websites like TrustPilot, and we can clearly see big exchanges there like Binance, Kraken, Bittrex, etc.
I don't think CZ or other owners would paid anything to BestChange for listing there or they gave them some percentage, but than again only they have few negative reviews on BestChange website.
Binance offers a
referral program, and my guess is the other listed exchanges do the same.
I used them as well before and I had good experience, but if same thing happened to me with 0.25 BTC I wouldn't be happy about it.
One solution is to never send them a large amount. That gives a slightly lower exchange rate and more transaction fees, but you won't risk having everything at once frozen.