Who called from 2153941995

They call but no one is on the other side of the line when I answer.

If you call back you can be put on their DO NOT CALL list.

If you call and opt out on their number you probably confirmed your number. They can make money when they sell list of phone numbers that have been confirmed for  lot of money.

Best option is to report them to "National Do Not Call Registry" at https://complaints.donotcall.gov.

It's allegedly a power company and they use multiple numbers.  They will keep calling using different numbers.

RETENTION DEPT showed up on the caller ID for this number.