Sorry about the pool collapse. Good luck with Intex. I don't think they will help you. I could be wrong, but you'll have to prove it was a manufacturing defect and not an improperly set up pool.
Curious as to what you did to "level" the ground under the pool. From your description, I believe you just dumped sand and then leveled it out and then set the pool on top of that. Sand is mentioned in the Intex pool instructions as something not to be used to level the ground. It can be used in a thin layer to soften the ground under a pool after the ground is leveled first. If you do you want to use sand you need to dig and level the ground from the highest points to the low points. Not by filling in the low spots. Sand will shift. By any chance were the pavers also put on top of the sand as well. They should be put on solid ground as the sand under them can shift. I am willing to bet that the bodies in motion caused the water to rock back and forth shifting the sand underneath the pool causing the supports to slip. This made the pool to fall out of level. All the water weight collected at that weak point and collapse of the pool was guaranteed to happen.
Taken directly from Intex....
Can sand be used to level the ground at the pool site?
[FONT=open_sans_regular]No. Sand has a tendency to shift, therefore causing the pool to lean to one side and creating stress on the pool frame. The legs of the pool will also sink into the sand and the pool will become unstable and possibly collapse causing personal injury or property damage.[/FONT]