Fake IRS scam/collection call. Left cheesy automated message on cell phone voicemail warning about "legal consequences"

I got the same call today. I got the same call today but it originally shows on my caller ID when calling me at 351 202 1738 they leave a message saying that if I don't call the 706 257 0 764 number then there will be legal consequences so I called the original number which was the 351 number and as soon as he picked up the phone he knew my name and he he told me that I owed over $3,000 in fraudulent taxes from 2012 to 2016 and said that he had sent 2 certified letters pertaining to this issue and I have never received one certified