I had a similar issue with Best Buy but they will not give you a full price credit, e.g. your authorization number which is actually your credit. It will only be a credit for a comparable TV on today's market. For example, I paid $2,000 for my TV in 2006 and they wanted to give me a $900 credit. This was because I had a 720p, 50", DLP and $900 was the going price per their records.
By the way, the same issue happened to me – the picture went out, they sent two bulbs, and a light engine and nothing worked. I actually was on project in Minneapolis and went directly to Best Buy’s corporate location to scream at them in person because it took nearly six weeks for them to authorize a replacement. A “senior executive resolution specialist” or some insanely titled person helped me and gave me a $100 gift card.
Now if you go to different Best Buy locations, they may interpret your credit amount differently. I did this per the advice of a sales rep a one Best Buy location. I had to go to four different locations before the sales person gave me credit for $2,000 and I got my current TV. I bought my replacement and ran the hell out of the store before she realized what she did was not per their policy.
Good luck and have a truck ready to take your TV and run!
Drell