What is “SC Topaz”? If you ordered topaz and got something else, you should get a refund. Of course, if it’s not topaz, it’s not allowed for the Master’s stone.
As for cutting suggestions, the only hint I can think of is to start by preforming to the specified L/W. This is a design intended for master-class cutters, and is expected to be difficult. Have you previously entered the Novice and Pre-master competitions?