KREEPY KRAULY SERVICE UNCONTACTABLE

I had a Hug Bug for many years that I was very happy with and it finally stopped working. I bought another one (it is one of the most expensive in the pool cleaner range). From day 1 the unit would get stuck on the step. I eventually got hold of Pentair who are the service agents (and it seems the founders of Kreepy Krauly) and took the unit in for repair. There was some problem which was fixed. Since then the unit climbs to the top of the pool and stays their sucking in air. I have been calling Pentair continuously and their number if permanently engaged. I have sent them messages through their web site with no success. I am not able to use the unit as the noise when it suck in air is driving both me and my neighbours mad, and I don't want to risk damaging my pump.