No response to logging a fault with after sales service

Bought a new built in Defy Oven in December, last week the bulb blew, when removing to replace found that the light fitting rivets had failed and the contacts had actually come lose in the fitting and shorted tripping the mains. Logged this on the Dey website under the contact us section. got the confirmation email ( without any reference number from the *** address ) within a few minutes but since then no response from Defy. The oven cannot be used as the broken fitting is a fire risk.