New wheels day….what am i doing wrong?

This is most frustrating! The second best feeling after new bike day is new wheels day obviously.

However, after fitting my lovely new hunt aero sprint wheels to my rourke to complete the classic modern retro look i turn the peddles and its really stiff, pedal backwards and the cassette hardly spins l, chain sags and falls off!

I refitted the campagnolo chorus cassette off my old wheels. Ive tried loosening the lockring, greasing the qr, spraying wd40 on moving parts. The brakes are clear of the rims. Ive just admitted defeat and had to leave the maiden voyage for another day. Have i done something wrong or should i contact hunt?

Thanks in advance