Defy 11, 6 burner gas stove. 6 years old

On or around Feb 2 2015 I was using the oven - temp 160C. I briefly left the kitchen & minutes later heard a bang & a crack. On returning to the kitchen I was horrified to find that the glass oven door had \exploded". The glass had turned black and this glass was all over the kitchen & dining room. If I had been in the vicinity I could have been hurt. The insulation was hanging off in strips.<br> On contacting Defy I was told that a technician would come out ( R450) to assess the damage. No assessment needed as I know what was wrong - the door exploded.. No explanation received or suggestion made.. Since then I have explored various avenues to try to solve my problem. Local appliance dealers have tried to get a new door & nothing.. Just constantly told"