From the very article you cite:
"Nvidia has to pay every GTX 970 owner $30 in compensation although the exact process for claiming the compensation has not been revealed yet. It is also not clear at this point as to how (and even if) buyers elsewhere in the world will be compensated."
So you're going to have to wait just a bit longer until details of the compensation are revealed.
I've bought 2 new 970's and gave them to my brother, (i don't have receipts) i bet they are going to make it difficult. Maybe they will limit the refund based on the serial number of the GPU?