It seemed sensible to go through an arbitration process since one is available. I will be interested to see what SoP says.
If their ruling supports my claim, then perhaps I will be one of the 80% of their decisions they say the airlines accept! It would certainly look better when going to court.

The Small Claims Track in the UK is an inexpensive process and allows for an 8% interest rate to be charged on the money owed so there is no disadvantage to waiting.

Of course the airline won't necessarily comply with a court ruling. Bott and Co had accumulated judgements of £20,000 against Small Planet and arranged for one of their aircraft to be impounded until the debts were paid..https://www.bottonline.co.uk/blog/small-planet-claims