Where did you get my address?

Both Steve and I are trying to get answers from Amazon, Target and Epsilon about how Target acquired our Amazon specific email addresses. Target phone reps told us the mail we got was a phish, Epsilon is refusing to acknowledge Target is a customer and Amazon has promised us “they’re looking into it.”
Meanwhile, an address of mine was transferred from one customer of an ESP to another customer of the same ESP. At first I was told I must have signed up for the mail; as proof I was provided with the data I supposedly signed up. When I explained no that wasn’t true, the abuse desk told me they had discovered there was a mistake and that “These two clients use the same 3rd party ESP and they had mixed the files.” I’m not actually sure who “they” refers to, but as long as they’ve untangled the files I am not going to argue. The sad part is that it took an escalation to Return Path (the IP sending the mail is certified) to get anyone to actually respond to my report of an address given to Company A being mailed by Company B.
On the flip side, mail showed up today that actually had a link for “how was I added?”

When you click on the link it shows exactly where the address came from and when it was added to the list.

It would be great if more companies provided this information to their recipients. I think it would probably decrease spam reports and make consumers feel more comfortable about how companies are collecting and using information.