Westin Nerf bar pad

I have Westin SS platinum nerf bars on my truck. Recently I had one of the black plastic pads blow off going down the road. I looked on the Westin site but cant find replacement pads. I bought this set from a buddy a few years ago. I believe they are 4" round...and have 3 steps per side (front door, rear door, front of truck box).

Do any of the vendors here carry Westin stuff, and can you find out what it would take to get a replacement step pad?

Thanks