Please help! Money claim made against me what do I go?

[Bee_ng]

Hi please can you help me I am a new small business owner I started my nail salon in November 2019 just before coronavirus and signed a ‘gentleman’s agreement’ with a landlord however I came to know that my landlord was subletting to me unlawfully as he divided his barber shop into two shops and sublet half to me which is a separate shop, I then found out who the actual landlords were and spoke to Savilles directly who have now repossessed the property from my landlord and have given me a contract directly however the landlord has now made a money claim against me for money saying I owe him during coronavirus period when he wasn’t being charged by the estate agents and I need help please.