Well i took a look into the matter and as you mention "we are not developers. we are med people", isn't there a possibility you misunderstood the devs? They did

Well i took a look into the matter and as you mention "we are not developers. we are med people", isn't there a possibility you misunderstood the devs? They did explain in their replies that the reason the site crashed for two weeks because of conflicts with the previous site which took a long time to resolve. And from what i understand, you "stopped trusting them" after this incident. I assume you figured it only worked on their servers by some scam and isn't gonna work on your servers. So i hope you see that this suspicion was very baseless. As for your paying of 75% of the payment, i assume that was AFTER you approved of the site on their servers. So they must have said "see? it's complete. now all we have to do is deploy to your servers" so it made sense to pay them. And so i am not going to blame you for paying them. What i do blame you for is not trusting them. But yes, generally it is best advised not to pay in advance (but i assume you only paid after seeing a working site). Either way, blaming this on freelancer.com doens't make any sense what so ever.