Bord gais fixed my boiler

Hi

I had my gas boiler fixed by a bord gais engineer recently.
I have been ringing bord gais looking for a cert for the work carried out on my gas boiler by their engineer and they refuse to give it to me.
They have modified my boiler in some way and god forbid if something ever went wrong i have nothin to say what they did.
I had no faith in the engineer he was a young man didnt really seem to know what problem was initially. Do i have a right to ask for a cert for work carried out is my question does anyone know.

I had a service done by them, and was given a cert listing exactly what they did and when. There was a name and it was signed by the engineer. Your request is more than reasonable. I would insist on this.

Thankyou for your reply