Why did Nick hang up the phone on Kilpspringer?

Klipspringer didn't even want to hear about the funeral.... he wanted his tennis shoes. Nick had no time for tennis shoes and false friends... he hung up on him.

“What I called up about was a pair of shoes I left there. I wonder if it’d be too much trouble to have the butler send them on. You see, they’re tennis shoes, and I’m sort of helpless without them. My address is care of B. F. ——”
I didn’t hear the rest of the name, because I hung up the receiver.