Is a fiberglass pool better than an in-ground pool with a liner?

We had a fiberglass pool installed 3 years ago. We are very disappointed. We live in suburban Philadelphia. Last winter our fiberglass pool "popped" out of the ground. It was full of water and the deep end popped up, lifting the concrete and all. Now there is pressure on the sides causing the sides to bow inward. What is most distressing about our situation is that NOBODY will help us. We contacted the installer only to be frustrated with broken appointments and NO SERVICE. We contacted the manufacturer (we now have cracks and chips from the pressure, which should be covered under our warranty)only to be told, that they are much too busy. We contacted other installers only to be told they also, are too busy making money "hand over fist" to be bothered with our problem. So, if you are considering a fiberglass pool in the Northeast area, I would strongly research your installer for response to service, consider the type of soil you have and definitely have a form of a french drainage system installed.