Help with Polyflam heating system, please

Can anyone help re Polyflam heating system, please?

We have a Polyflam system which was in the house when we bought it. The fire bricks inside the cavity need replacing as they have cracked - one "disappeared" when the chimney was swept 3 years ago, but, of course, the ramoneur knew nothing about that! For the last 2 years, we have been trying to get a replacement set of fire bricks, and have placed orders repeatedly but never get anywhere. Last year, we got a set which didn't fit. This year, the supplier took our order in July and promised they would arrive before we returned to the UK in September. Despite emails, etc, we still have no fire bricks and we were told today (when we called at the showrooms) that it was "complicated" dealing with Polyflam! We've tried 3 different suppliers so far but no joy.

Does anyone have any experience of this system, please? We have been very pleased with its performance until the bricks cracked, but now we're left unable to use it.