Chelino pram

I had purchased a Chelino pram for my first born from take a lot and over time it begin to collapse whilst it was in use. I contacted Chelino and they replaced it with a new one. The new one is not even a year old and is beginning to do the same thing. I contacted them again and was told that it’s an unusual problem but it has yet to be resolved. My second born almost got hurt the other day as it almost collapsed with him inside. They are not being very forthcoming or helpful as I find it insist that it’s happening with and second pram and their response to me is that it’s not a normal fault.