ELBA 90cm electric oven 5plate Gas hob

We bought a 5plate 90cm oven from Hirschs online R14999 two month into having the electric oven 5 plate gas stove the Internal Grid snapped in half! To get a replacement from Hirschs is an absolute joke! They want a COC from my registered Electrician to say the installation was done to standard!! What has the installation got to do with the grid that snapped!? Help me make sense of this?! Now they say that Elba requires this information?? What absolute nonsense! It’s left a bad taste for this brand with me