I thought the referee was the final arbitor? If this is the case and the referee was satisfied that Ian Senior could run the line FS's objection to accept this arrangement is a de facto refusal to continue, irrespective as to what he actually said. So, logically, the game should've been awarded to us by the referee today, with Colwyn Bay having the option to appeal the decision. That said, not to have arrangements for a substitute official at a senior football game is p1ss poor.
The key here is whether the referee abandoned the match. If he did it's a replay. If the match couldn't continue because Frank didn't want Ian Senior on the line despite the ref being ok with it, it's a forfeiture in our favour.