How does one go about making sure that a company is legit and not just a shell or scam?

The industry was a bait and switch scam from the beginning, mostly used for illegal activity.

So everything you can do to avoid a scam or a shady character is worth something. 

I don't think it means it is a scam, just a bit annoying.

However, this isn't the wild wild west anymore where real estate scams happens to your cousin brother's friend on a weekly basis. 

Its an outright scam that they pulled on you and you should fire them immediately.

(Or a lot if you're dealing with a scam turnkey company, of which, unfortunately, there are a decent number.)BRRRR is much more active, you buy a fixer as you note, oversee the rehab yourself and then either manage yourself or find a manager for. 

Hey @Olivia ArmstrongBuy downs are not a scam!

This is what can go wrong when you have beginners wholesaling who have no training in real estate, no experienced managing broker to go to for advice, no license, no E&O insurance, no knowledge of how to avoid scams, no regulatory body to answer to, no relationships with other quality people in the industry like title companies, lenders, contractors that they can refer to help people, etc. 

The amount of spam & scams ebbs and flows in response to things that might have little to do with BP, and again sometimes that means response is a trailing effect.