the good news is:
1. you now know where to NOT go for advice, parts and accessories.
2. the bobbins you bought will work, so you haven't lost anything.
3. the price you paid is about average according to my own personal search the last time i needed to buy bobbins. it's ridiculous ... outrageous, really ... but about average.
most important: you now know where to NOT go for advice, parts and accessories. ;-)