If this ever went to litigation, I'll eat my hat. Gemini are owned by APCOA and APCOA do NOT litigate. Just go through the motions and after the inevitable IAS rejection, you can safely ignore all debt recovery letters. Debt collectors are powerless to do anything except to try and intimidate the low-hanging fruit on the gullible tree into paying ut of ignorance and fear.
Eventually they will give up.
If you want to understand why APCOA don't bother wasting their time and money with litigation, have a read of this thread which shows how much they make from the 'Gullibles' who pay up anyway:
FYI, FoI request for data on Penalty Notices issued by APCOA on Southwestern Railway car parks
