Maciek,

You are correct in common practice:
you open the shipment and then find it's non-conforming material (however Pioneer will point out that the packing list did indicate what was shipped).


It's the size (quantity) of your shipment that causes them to argue i';; wager. If you are not a "company" of any size they think of you as a hobby-ist and hope that "barking" real loud will chase you away.

If you insist they will accept the return (insist means escalate the problem up a level or two and DON'T YELL! Be "far too nice" (that a lot meaner) and have a solution fair to both parties ready.

BTW: What is your alternative if ATMEL doesn't ship the intended part any longer?

regards,
p