If you are supposed to have a pilot on all the time, I'd get this seen to pretty damn quick. If a minute were to turn into much more, you could end up with a lot of unburnt gas waiitng for the next spark from your pcb igniter. I would hope that your pcb is having to operate a solenoid vale for the pilot light supply, but if not, I would expect, with my limited knowledge of these things, that it could be potentially very dangerious. Its not warm in most places at the moment, so I'm doubting if the pilot light really should go out in this current climate. If you can't turn the piloot light right off, I'd seriously consider turning the gas supply to the whole boiler off now until its been seen to or until you have more facts at your disposal as to how the boiler should be operating.
I'm no expert. I think I'd get one in if I were you. Ring Corgi if you're not happy with what your maintenance man has done or told you. Register your dissatisfaction in writing ASAP.