I have never expected a replacement bag, at the time I picked up my luggage when one of my bags is damaged. It is a chance you take when you check a bag. I buy Samsonite, Travelpro and Tumi and have always gotten free repairs when I take my bags to an authorized service center. Next time, instead of ranting at the CSR working the Bag desk, ask him where UA sends damaged bags for repair at PDX and take the bag there. You will get a lot farther with that approach that ragging on a CSR who didn't have anything to do with the damage.
In DEN, I use Zion Luggage on Chambers Road when something is broken on the Samsonite and Travelpro bags. They fix it, I never pay for it. When I have had a problem with my Tumi I take it back to Nordstrom. . .
I went elsewhere and bought my stepdad a serviceable bag to get them home, but it is preposterous to me that United doesn't have a simple way to replace a cheap bag with a cheap bag.
You think UA ought to be in the luggage business?? Come on. . .