Email is not a perfect communication method. Odds are that Turbine sent you an email. Either you gave Turbine a defective email address. Or the email was intercepted and destroyed in transit. I suspect the ticket has been closed at this point.
The other issue is that Turbine will often send you a ticket confirmation email shortly after submission. It is a machine generated form letter. You have to reply to this email to queue your ticket for a human. Since they are form emails, they are more likely to be assigned the "Spam" tag and destroyed by either your ISP or one of the email carriers between Turbine and you. Most spam never gets put in your spam folder.
My suggestion is that you call Turbine on the telephone:
http://support.turbine.com/ics/support/contactUs.asp
when the lines are open. That is what I did to resolve the issue Turbine's web store rejecting my Wells Fargo Visa card. Phone wait time on December 20, 2013 were long. It took me about 20 minutes to get to one their nice humans. I call Turbine on the telephone because I have no patience. I want it fixed NOW not hours or days from now.
Alternatively you could in a second email ticket. Be sure to include the ticket number for the 3 week old ticket. Ask what is going on. No idea how long it takes Turbine to respond to a status inquiry ticket. It would not surprise me if Turbine has 1-2 week turn around on email tickets. Helms Deep launched not long ago.
It is the holiday season. People like me are trying to advantage of some the nifty sales Turbine is running. Having problems and needing to contact Turbine for help. No idea how many people had payment issues like I did. I used up 5-10 minutes of a customer service representative's time to resolve my issue. I added to the hold time for phone support.
Unless stated otherwise, all content in this post is My Personal Opinion.