Bests & Worsts Reviews from Amazon

This is the worst card stock I've ever tried!!! It is flimsy and will not die cut without tearing! The company, My Office Innovations, will not issue a refund because I "opened the package" and also used it"!? I used 1/2 sheet of the 100; how would I find out it was defective if I didn't open the package & try it?? They refuse to issue any part of the $15.66 I paid them for this defective product. Buyer beware.