What is the return policy at costco??? Swingset we bought 2 years ago is DANGEROUS!!!!! PLEASE READ!?

We bought a rainbow play center from Costco two summers ago, and from day one my youngest child would go out and play for the day and get cut on his arm or leg at least once a week. He was 2 at the time, now 4, but we attributed it to him playing outside. Well we found out why he was getting cut this weekend. My husband was playing wiht the boys and reached through the playhouse between two boards and cut his arm up AWFUL!!! There are two staples/nails sticking from the inside OUT of a board on the treehouse portion. This is extermely upsetting. WE looked again and there are three boards like this. We paid $1300 for this set from Costco, can we return it? Or do they not honor that after two years? A replacement would be fine with us, this set makes us very weary, like maybe defective...so what will costco do for us?