I am unable to return the cat condo, since I live alone and I am a senior. Maybe the best option is a reduction in the amount that I paid. I know that it will not solve the problem with one of the kitty's hurting himself. I noticed last eve that one of the kittens jumped from my bed to the condo and the condo started to fall forward. I was there to catch and hold steady. 
I wish I had not given the other away to someone, but it is far too late. 
I have no idea how much compensation will replace  my problems with is likely to occur. They are not even a year old ...I will leave the offer to you.

Pros: this is an addendum to others I have written