UPDATE:
Mate had a response direct from Mahle Germany stating that the warranty is 2 years and suggesting that the matter is resolved with the company where he purchased the bike.
They stated, slightly tongue in cheek I reckon, that before Brexit every product has a 12 month warranty and 24 months for electronic devices. As the UK gov is far too busy to unwind EU legislation, Ribble are talking a load of piffle and balderdash.