Breach of Contract

I purchased a generator from Genpower April 2014<br> I requested installation of the generator as well as a COC( Certificate of Compliance ) to comply with electrical installation requirements<br> They confirmed in writing that the COC is included in all installation<br> Three months after installation the automatic start failed Genpower fixed a switch <br> How do you supply a COC with a faulty ? switch ?<br> <br> In December I purchased another generator<br> I was in the shop when site inspection and the COC request was scheduled on a public holiday<br> When the public holiday was queried the installation department confirmed all details ( date address and the COC request<br> They did not pitch on the public holiday as the booking was not confirmed according to the installation department<br> <br> I received the installation quote very similar to the first installation quote and proceeded to pay them <br> <br> Installation soon followed and when I queried the COC I was told that it was not included<br> <br> The installation was done so poorly that all the wires have melted after the first use <br> <br> I want the COC which I have paid for