Called us with a auto tuned voice saying they're from the US Treasury, Dept of Legal Services and having been trying to reach me in regards to an important legal matter. I'm pretty sure they usually mail stuff if it's important. Not sure if I should trust this.

Report the Calls to the real IRS here:

IRS:   http://www.irs.gov/

http://www.irs.gov/uac/Report-Phishing
phishing@irs.gov
http://www.treasury.gov/tigta/

http://www.irs.gov/uac/Tax-Scams-Consumer-Alerts
http://800notes.com/forum/ta-8c2f64bf2b91fa5/irs-warns-of-telephone-scam

•If you owe federal taxes, or think you might owe taxes, hang up and call the IRS at 800-829-1040. IRS workers can help you with your payment questions.
•If you don’t owe taxes, call and report the incident to the Treasury Inspector General for Tax Administration at 800-366-4484.
•You can also file a complaint with the Federal Trade Commission at FTC.gov. Add "IRS Telephone Scam" to the comments in your complaint.