I am in the same position. I have stopped playing it as well, and hope that they will fix it soon. I don't know if there's any way to track who purchased CQ, but if there was, the right thing to do would be to give those people a discount on Stacking. This would incentivize us to stick with DF, but also be a great good-will gesture for this error. I would like to finish CQ, but I don't exactly have the 3-4 hours to restart it.
I hope that they do the right thing for thier customers/fans, as this has left a seriously sour taste in my mouth, as I haven't been able to play CQ for a month now, and had to pay $20 (including expansion) just to get stuck just past halfway through!!!