Debt Validation question

[Anonymous]

A few weeks ago I sent out DV letters to all the collection accounts on my CR. I sent them all CMRRR.  Today I received one back that says "Return to sender not deliverable as addressed  unable to forward"   Now what?  I pulled an annual credit report and that is the address showing for them on my CR.

This one I really need to get validated because it is for a Dr i never heard of and is for $544 (my biggest one).  I am pretty sure it is from my ex taking my son to the dr and putting my ssn as the responsible party but his address on the registration. Urgghhhh......

Any ideas of what to do next?

[Anonymous]

Whats the name of the CA?

[Anonymous]

It is a local one here where I live. In fact it is showing as the name of the CA only being the county..  It says "Montgomery County CB"  i am guessing that is Montgomery county collections bureau maybe?

[Anonymous]

I think I found them online. I guess I will try the address listed there.

[Anonymous]

So I sent them an email via their contact us requesting they validate the debt. My next question would be do I have any recourse if it was my ex using my ssn?  is that legal? 

Per our divorce we are both responsible for 50% of their medical. And I believe it states which ever of us takes them to the dr would give the other party the bill to pay their 50%, not put the other party down as the responsbile party.