Card-jacked after buying PLR

I'm wondering if anyone here would happen to be well-versed in the legal aspects of dealing with banks/credit card companies and could offer me tips or clarification on handling things with the bank.

My credit card number was stolen and fraudulent charges (hundreds of dollars total) made on March 15 and March 21. I discovered the charges at the end of March and immediately called the Wells Fargo fraud line to report it. The rep told me that I would receive a form in the mail from them in a few days that I should use to convey all the facts to them and report the fraud in writing.

Instead, I received a letter today wherein they stated "our investigation reveals that you provided apparent authority to the person or entity that initiated the transactions you have claimed as fraud. As a result, the transactions in question are valid and will remain on your account."

I went absolutely spastic when I saw this, because I definitely did NOT authorize the charges, which are completely foreign to me, and have no idea on what basis the bank is trying to claim that I would have authorized them (and am dying to know).

Another thing that I'm very curious about is whether it is possible that Wells Fargo has already violated some federal credit laws by "concluding" things that are highly adverse to me and denying the claim before even talking to me or letting me state my position and the facts. I'm wondering if there are solid grounds for a suit or punitive fines here.

By law, don't they have to cooperate with me in an investigation? The letter did give a phone number I could call, and I did call it but only got a "fraud prevention representative" who was just a claims rep and not any kind of fraud investigator, which is who I want to talk to. I was told I can call tomorrow and talk to a "claims specialist" which apparently is the same thing there as a fraud examiner, but I have a bad feeling that they are going to treat me as the guilty party (since they have already) and not give me access to whatever information they are claiming led them to believe that I authorized the charges... and if they do this, I am pretty confident that they will be violating some really basic rights of mine as a cardholder.

I'm willing to give them a sworn affidavit and file a police report and whatever else like that they may want, but I am not going to let them call me a liar, basically, which is what the letter they sent does, and stick me with hundreds of dollars in charges that some scumbag credit card thief stole from me after I had worked hard paying the card down for months.

The reason I mentioned PLR is because I know where the fraud had to have come from: the card was only exposed on the net (or anywhere else besides a major car rental agency one time in August 2011) one single time, and that was when I used it in January to buy a $10 PLR package from someone who, unfortunately, is a member here. Now, of course I'm not saying that I think that member necessarily is the one who pulled the fraud, because obviously it could easily have been someone else who had hacked into his data stream or something to get my number, but I think it's safe to say that his payment channel is definitely not secure.

The charges were made to a website that in the bank records appears as "www.eastwestenterp" which probably refers to eastwestenterprisesllc (dot) com which is a retail electronics site that is kind of mysterious for a retail store that ships stuff, because it has no way other than email addresses to contact them. I mean there is no info at all on the site about who they are, where they are, what their address is, or anything like that. When I tried to look up the Whois data, I found it has the "Domains By Proxy" block on it so I can't get any info.

Anyway, sorry for the long saga, but does anyone know

1. Whether there is a chance I have a lawsuit against Wells Fargo for some kind of cardholder rights violation if they refuse to cover the fraud and refuse to share with me all information they have in the matter, and

2. What the procedure is on things like this and what options I have (they're not very good about informing me of those things, and I've never gone through this before so I'm pretty uninitiated).

Thanks in advance,
A.C.