Asking CAB for advice on civil parking matters is an exercise in futility. As for offering to pay the £20, is an admission of liability which you must never do!!!
Your saving grace is that this is GroupNexus (CP Plus Ltd) and they will eventually escalate it to a county court claim. However, they use DCB Legal as their bulk litigator of preference. All you need to know is that any claim issued by DCB Legal will never reach a hearing in court. As long as it is defended, especially if you follow our advice and use the template we provide, it will either be struck out or discontinued before they have to pay the £27 trial fee.
This is not guesswork. I always take on bets at 100-1 odds, if anyone cares to me up, that the claim will never be heard in court.
A POPLA rejection is not binding on you. DO NOT pay it. You will next start receiving useless debt recovery letters which you can safely ignore. Debt collectors are powerless to do anything except to try and persuade the los-hanging fruit on the gullible tree to pay up out of ignorance and fear.
Come back when you receive a Letter of Claim (LoC) from DCB Legal.
Just to answer some of your other questions, assuming you are the first of tens of thousands of DCB Legal initiated claims that is defended and still reaches court, even if you were unsuccessful, the £70 added fake fee is never allowed and apart from fixed costs of £35 Claim Application Fee and £50 fixed legal costs, you would owe ~£200. As long as the CCJ amount is paid in full within 30 days of judgement, there is nothing on your credit file. It is completely expunged.
The only "harassment" a debt collector can do is to send you useless letters. As I've already mentioned, you can safely ignore any letters from debt collectors. They are not a party to the contract allegedly breached by the driver and are therefore powerless to actually do anything.
For future reference, next time you receive a PCN from an unregulated private parking firm, DO NOT identify the driver. They have no idea who the driver is unless you, the registered keeper blabs that information to them.
As for Pure Gym, we see so many PCNs issued at their locations, I would advise you to cancel your membership and tell them why. Getting invoiced for £100 by a third party because their chosen car park operator is a scummy bunch of ex-clampers who are out to scam their customers, is not good for their business.
