If you paid the PSL to Holdings, then it's them that you should be taking to court. Actually, given Fisher's claim that Holdings are the club, I'd be tempted to just take action against them anyway.
Claims of up to £300 cost £25 to lodge, using the online version of the County Court.
https://www.gov.uk/make-court-claim-for-money/court-fees
I'd start with a
recorded delivery letter to TF, c/o Coventry City Football Club (Holdings) Ltd. along these lines:
Sir,
Given that you have now decided to move Coventry City Football Club from the Ricoh Arena, I request and require an immediate refund of the <amount> that I paid for a PSL.
If no refund is received within fourteen days, I will lodge a claim without further notice in the County Court for this amount, plus costs, plus statutory interest.
Yours...
Keep a copy. If they don't pay within fourteen days, lodge the claim with MCOL. If they don't respond to the claim with a defence, judgement will be made in your favour in any case. Then there's any number of options to get paid, including sending the bailiffs in!
If anyone fancies a crack at it, PM me and I'd be happy to help out. I've been down this road before against a dodgy car dealer and a credit card company and won.
Can't promise you'd win - but I'd pay half just to see the defence in any case. You'll need proof of payment though.
It would be a right pain for SISU to suddenly have to defend a few hundred of these. Because it's a small claim, each side pays it's own costs, generally speaking. This might hurt them.