Middle pane shattered

[gc100]

We have some very large cortizo sliding windows/doors and in our house. They are triple glazed and one of the middle panes has just shattered for no apparent reason. They’ve been installed now for around 4 years. 
The manufacturer is claiming they don’t cover any form of broken glass and they are very difficult to deal with and often simply never reply to emails and only occasionally pick up the phone .
They’ve given us a quote of 4.5k to replace which is about the same aa all 3 sliding doors costs us new 4 years ago! 
I known the prices have gone since Covid and the at but that seems crazy.

Unfortunately due to the slim design of them the frame is bonded to the glass and I can’t see what other options I might have.

Any ideas ? 

Edited Tuesday at 14:39 by gc100

[Mr Punter]

You could try another fabricator.  They have over 30.

[Andehh]

Home insurance policy? Accidental damage etc? 

[DamonHD]

Seems possibly to have been a manufacturing fault, and the units shipped to you were not fit for use for a reasonable lifespan.  You may be due at least partial refund?

 

Our triple glazing was a bit explody - I think because it was a new manufacturing line - and we had no arguments at all getting things fixed under our warranty.

 

https://www.earth.org.uk/triple-glazing-3G.html#Failures