Missing Mortgage Interest Statement from 3 years ago. Loan is paid off and the mortgage company has changed hands. The customer service will not let me in without a current, active loan number. How can I get the info I need?

what do you need it for? how exact does it have to be? 

if you have the statement from 4 years ago, take the ending balance times the interest rate and THAT will be quite close to the interest from 3 years ago.  it will be SLIGHTLY high.

If you have the statement from 2 years ago, take the beginning balance times the interest rate and THAT will be quite close to the interest from 3 years ago. it will be SLIGHTLY low.

I am assuming you have a fixed rate loan. 

If you received a 1098 statement for mortgage interest, a copy was also sent to the IRS.  You should be able to retrieve a transcript of that from the IRS.

https://www.irs.gov/individuals/get-transcript