I'll chip in here, I wouldn't want to be forced to buy thangles to complete the block. How many do you need, my guess very few and you'll be left with a package, you will use at some point. Same with fancy rulers... However if it was stated from the beginning you would need 'x-y-z', but it doesn't sound like you were.
Now my peeve for the day I need white 120" or 108" muslin, can I find it 'no'. I can find all the fancy stuff for $17.00 a yard. I finally broke down and bought one of the fancy ones and find it very hard to hand quilt. In my mind I can make more tops if I don't spend $50.00 on back. So now I go the mail-order route and get the batting because it is $10.00 cheeper mail-order. So local quilt shop lost business.