This left the handle wobbly, and a bit of metal tube with a sharp end would keep coming away from the case, that jabbed me in the leg occasionally when I was carrying it.
The case is a Samsonite. It had a three-year guarantee, but it's older than that and I couldn't find the receipt anyway. I emailed Samsonite regardless, just on the off-chance that they might sell me a replacement part, or point me at a local repair centre.
They didn't sell me a spare part. They just sent me two, in the post, for free. So, tonight I put my Big Black Suitcase back into commission, save myself a chunk of cash on a new case, avoid gashing myself in the leg, and post a message on the internet telling people that if they've got a choice of suitcases, they should probably buy Samsonite.