No need, at this point. This will never get as far as a hearing. If it ever did, which it won't, they would have to give a witness statement which is where you can challenge anything they claim. For now, the Particulars of Claim (PoC) are defective.
The PoC must give a concise reason for the claim and you must be able to understand the claim fully from those PoC. You have to imagine that you know nothing at all about this claim and the very first you know about it is the PoC.
They cannot argue that you should have known about it from previous correspondence. The actual PoC must give enough information for you to be able to plead a defence. If you read the defence provided (authored with the assistance of a long serving district judge) you will see that the only defence that can be made is that a proper defence cannot be pleaded because of the defective PoC which are in breach of CPR 16.4.
These bulk litigation companies could, if they wanted to, submit further more detailed PoC within 14 days of service of the claim. They choose not to. They are relying on the hope that you are low-hanging fruit on the gullible tree and can be intimidated into paying up out of ignorance and fear. Sadly, the vast majority of recipients of a claim will either bury their heads in the sand or screw up on how to respond and the Claimant gets a judgement in default. These bulk litigators issue hundreds of thousands of these small claims every year.
Of the minority of cases that manage to find their way here for advice, preferably before any response has been made, we successfully advise almost every single one to a successful conclusion. In the majority of cases, it ends with a discontinuation. Some are struck out and of the very few that ever get as far as a hearing in front of a judge, most of those are won.
So, for now, just do as advised and if it ever gets to the point you need to mention the fact that you paid £100, I will eat my hat and assist you on how to put that point across in your witness statement.
Can you please confirm whether the N1SDT Claim Form with the PoC was signed by Sarah Ensall as 'Head of Legal'? IF so, I have further advice for you which will put DCB Legal on the back foot. She is not authorised to conduct litigation and is in breach of the Legal Services Act 2007, which is a criminal offence. You can require them to cure the defect by having the claim reissued once signed by someone who is authorised to conduct litigation and also report them to the SRA for the LSA breach. This is all due to a very recent binding high court appeal case that finally confirmed that anyone conducting litigation must be authorised, as it is a reserved legal activity. Up until now, these firms have been using unauthorised individuals who think that they can conduct litigation under the supervision of their solicitor. They cannot.