Tenant with ccj taking me to court

I have a very difficult EX tenant,threating legal action,with section 11 of the tenant landlord act,if nearly 7k isn’t paid in rent paid,£350in electric in TWO WEEK’S, PLUS £500 for a silly piece carpet and underlay.

I have all evidence of all reports and instantly sorting of any issues,these tenants had( previous tenant had NO issues at all).

I feel they are trying to make a quick out of court pound.
Also I have APPARENTLY found out I have no cover for this issue through my agents,I’m a first time landlord feeling my way so ANY help would be so great full.

I don’t understand this. If they are an ex-tenant, on what basis are the claiming this? Are they saying that because they believe you failed to maintain the property you should repay them the rent and other costs? Are they saying that they will claim a Rent Repayment Order from you for some reason or are they perhaps saying that you didn’t protect their deposit and they are claiming a penalty? More clarity needed here.

First time landlord . Join the NRLA if not in it