NTBAY 3 Pieces Seersucker Duvet Cover Set, Super Soft Microfiber, Nature Simple Style, Cream, King

I just got the king duvet cover, but we did not receive the shams. It says it is a three set. Can’t find the contact information for the seller?

How does it hold up to pet (dog) nails jumping up on the bed?

For customers who’ve had it for longer than 3 months... How is the material holding up?

Is this a duvet slip or an insert? Do i need to purchase additional items?