Problem Tenant

Rent Arrears

He became a tenant in March 2020 (start of lockdown last year). Unbeknown to us our old tenant had been sub letting to him for 3 years. We supplied him with a 6 month assured shorthold tenancy agreement on 20 March 2020. We were unable to proceed with an EPC or Gas Safety Certificate because of lockdown and he has been uncooparative since with regards to us trying to get these completed. He won't reply to calls or texts. He stopped paying Rent in July 2020 and we issued him with a section 21 notice in October 2020. We still haven't been able to complete EPC or Gas Safety. We are reliably informed that he is still working although he has used the pandemic as an excuse for not paying his rent. I would be really grateful if you could advise us on how we proceed with this. Thank you