Hi,I'm Zoey and I'll be assisting you. I'm reviewing your question now. Please be patient while I research and compose a reply for you.
I think that you are probably talking about Charge One, also known as Geek Support, in Las Vegas, Nevada. If so, they are a legitimate company. The Better Business Bureau has been aware of them since June 2015. They have had several complaints, some of which the company did resolve. For that reason, on their scale from A to F, the BBB has given this company a B- rating. So it rates somewhere between good and fair as far as computer companies go.
All of that said, scammers frequently use the names of legitimate companies to bolster their credibility and swindle you. The red flag here is that this company made unsolicited contact with you and told you that your firewall has crashed.
That's the sign of a scammer. No outside company would have any idea of what is going in within your computer unless/until you give them remote access to it. So any unsolicited out of the blue caller warning you that something is going wrong in your computer is an outright lie.
In the best case scenario, this is just an unlawful marketing technique to scare you into signing up with them for an annual contract you really don't need. In the worst case scenario, you're dealing with a scammer who can plant malware into your computer which will log your key stroke so that the scammer can get your passwords, hack into your accounts and rob you blind.
Either way, you want to avoid a company that will do this. You should never grant remote access to any computer company you haven't fully vetted first. And you should never grant remote access to any tech company that makes unsolicited contact with you and who claims to already know that you have problems in your computer.
Finally, you may also see an occasional pop-up on your computer screen, not from your anti-virus software, telling you that there is a virus in your computer and giving you a number which is supposedly Microsoft or some company working with Microsoft. These are all scams. Not even Microsoft knows what's going on with your computer. They don't monitor Windows computers in that way. These pop-ups are trojans which are embedded in various websites. Their purpose is to convince you to call a scammer because you think you are in urgent need of tech support.
Just checking in to see if you need more help or any clarification of my answer. If so, please reply here on this question thread.