HMMM, After all that... Update failed? any suggestions?

Hello New here to the forum. I have just purchased ,, I 1000 and It don't like my truck.. LOL All kidding aside, It said non compatible. Been on hold for 1, 5 min. hour so far with tech support... Hope you can help here on forums. 2008 Sierra GMC Denali 1500 6.2 liter. Before I purchased this tuner ...