Insurance, Who do I complain to?

Hi Folks, hope you can help!
We pay a monthly (Direct Debit) payment to cover repairs/service for our double oven.
Early April we had to call out an engineer, as both ovens were "misbehaving".
Engineer explained, "both thermo switches were faulty & main oven seal was perished".
The Engineer told us, "off the record" I do not think we can get parts for this model anymore.
Cut a long story short! We are still without proper use of either oven. My Wife has made at least 12 calls to both the Service Dept & Ins Company. Both promised to investigate & call Her back. No responses to date.
I started an email "contact" with both parties, & keep getting conflicting replys.
The policy states, "repair or replace, with the equivilent". Neither has happened as yet.
I've made a formal complaint to both parties, no response.
Is there a "Governing Body" I can raise this with, Consmer Direct cannot help!
Grateful for any advice, please.
Bob.k

Hi Tony, no, this is an independent cover. It is supplied by one of the major insurance companys. We took the policy after the first 12 months, & have been using this company for some years to cover major appliances. Each appliance is on it "own" policy.
Bearing in mind, we wanted to use a "reputable company", this was the most cost effective way to gain cover.
They will only cover an appliance for a max of 7 years. Our oven is mid way through its
6th year. Therefore, they have been supplying cover for 5 1/2years.

Regards, Bob.k