Dominator Lite does not work

I've had no response to my queries relating to the Dominator Lite.

I bought a Dominator Lite in October, and I was told it would work with the 0.25kW pump kit, but the cleaner moves a short distance then stops and stays in the same spot indefinitely. The filter is showing 8 psi, but the lowest it goes is 5 psi, immediately after backwashing, so not much difference.

I'd like to know what I need to do to get this to work properly. It has now been sitting unusable for 3 months and I'm having to vacuum the pool by hand.