In my opinion you should reply to this letter - and all letters that fail to answer your requests - by politely restating your request in writing again.(posted 8493 days ago)Add a paragraph noting that you made this request in letters dated xx, xx, xx and xx and that you will be able to help DLA as soon as they supply the information. This will politely let any judge know exactly what it is you have had to deal with.
Then sit back and wait. If you want to be a little more proactive, you could sit back and wait after reading the Litigation Handbook (details in the Who Helps? | Books that Help section of this site) on preparing defences and counterclaims so that you are more prepared should DLA really feel like taking you on.
I suspect they won't but that depends on your circumstances.
Lee