How do I find the address of Next Generation Debt Settlement that scammed us?

I wrote about Next Generation Debit Settlement a couple of months ago asking for advice on how to get our money back from them. They have $2400.00 of our money. You suggested following steps in your program, one of which is to send a certified letter to the company. I sent a letter, which is now returned because they are not at that address.

The address I sent it to is: Next Generation Debit Settlement Group
20 Trueman
Suite 109
Irvin,e CA. 92620

What is the best way to proceed from here?

Is there a valid address for them?

I did cancell business with them, and they sent an e-mail a month ago saying they had filed a refund request. I have asked many time to talk to someone, but I’m always told they would submit a claim, and someone would get a hold of me. I don’t even know who is in charge of this company.

Does anyone have information I can use to try to get my money back?

LeeAnn