Check the accuracy of the thermometer you used in the mash. Also, with the additional malts (above the 2 row) the yeast simply could have fermented all it can.
Was the fermenting beer temp been at 70F, or was the room it was in at 70F? Depending on the age of the yeast you pitched, if you didn't make a starter, you could have under-pitched. What oxygenation method did you use?
I wouldn't shake it at all (shaking is bad, mmkay). IF anything a gentle swirl might rouse some of the yeast. But you also could simply have fermented what's available in the batch. Give it another week, or two, check it again and then bottle/keg it up.