I kept receiving phone calls from this number, but every time I picked up no one answered. So I blocked them and reported the number to my carrier.

It's a scam claiming to be a government agency, Fraud Division, Financial Collection Dept. A guy and sometimes a women with a Indian(from india) accent. Total Scam do not give them any info! they might have the last 4 of your social but that's all do not give them the rest!

I got a call from this number today at work and like you said they had the last 4 digits of my social security number which I refused to verify. They also had my cell phone number.  The man had a very heavy Indian accent and got very annoyed when I kept asking what company he was calling from and what city he was calling from.  I told him I was at work and could not speak to him now and that I would call him back later.  I did some research on the phone number and even though he told me he was calling from New York, New York the call actually is from a private number in Brooklyn, New York. I'm glad I didn't give any information.

same call same people and answers told them nothing SCAM SCAM SCAM

A guy from ESA Association called and said we needed to join his company, we assume that it is some environmental sales call, they guy said that there was a $37,000 fine or imprisionment for not joining, that it was a law.
He told us we needed to go to his website and join ASAP. He was very hard to understand.