Honestly, this sounds like a really bad situation from the start. There might be more to this, but this is essentially what I took away from all this.
- The players have been playing these characters for a good while and had an overdeveloped sense of invincibility.
- As the GM you felt the need to maybe show them that no matter how powerful they think they are, there are always bigger fish.
- The players made a colossally bad decision in trying to cheat their Mr Johnson.
- The Mr Johnson(unknown to them working for a huge megacorp) responds by sending a squad to "furiously negotiate" with them.
This is where it starts to get really messed up, and sounds more than a little personal to me. You had a beautiful opportunity to make the Mr Johnson seem mysteriously sinister. As in, he could have sent them a message along the lines of "I know what you did, where you are, and I can completely erase you, but I'll let you learn from this mistake if you return the goods". Throw in some personal details to show that he has huge resources and is NOT joking around, and they would have had a chance to avoid the clusterfuck that happened. However, sending a strike team against the players in response for an action of theirs really sends the message that you're trying to punish them.
Beating up the Mr Johnson was dumb. Defeating the strike team is enough of a message that they are experienced and formidable runners. Plus it would have put them in a good strong position to negotiate with Mr Johnson. But the choice they made was dumb. I agree there.
However, I have to agree with All4BigGuns here, dropping them in a park when they are 1 breath away from dying, that happens to be "infested" with vampires(your word) is a massive dick move. That is basically saying "I am going to try to kill your characters". The GM SHOULD NEVER play against the players. If they fuck up, react appropriately and feel free to play it out in character as whatever the HTR team/Mr Johnson/Megacorp/LoneStar/etc would realistically do. However, actually trying to kill your players(and I do not for one moment believe you didn't expect at least some of them to die) just to teach them a lesson is a dick move.
Lastly, the Street Doc charging that much to heal them is a bit steep. Could be projecting, but it seems that he had an antagonistic attitude to start with, when in reality he should have been entirely neutral unless he was connected to Mr Johnson.
Anyways, /end criticism. Just seems that your players were arrogant, and you unfortunately reacted in what can easily come across as a petty way, trying to punish the players and not the characters. But that's just how I see it.