Thank you for your patience.
This private land fine is from members of the International Parking Community (IPC). The private charges are based on contract law and allege that the driver breached a contractual term (e.g. an implied promise, such as to display a permit or not to overstay a 2 hour free period). Such contracts can be enforceable in the county court, but are defendable.
You will need to put in a complaint to the landowner about the charges, i.e. the property owner. This can sometimes work and do not underestimate the power of this, especially as you have just moved in, own a parking permit and there is no mention of it in your tenancy agreement.
Ideally, when you appealed to them, you should not have named yourself as the driver because now they know the party who allegedly entered into a contract with them, and can pursue you. If they didn't know who the driver was, then they can't pursue you. However the Protection of Freedoms Act 2012 (POFA) does since allow them to go after the “Keeper” (not the registered keeper) if they don't know who the driver was but there are a few hurdles they must jump in order to do this such as meeting all the requirements of Schedule 4 of POFA particularly the serving of the correct notices (Sec 7-9) with exactly the right information in them. This is the part they do not get right preventing them from making the keeper liable. But as they know it was you now, you can move to the next stage.
It is up to you, but it is advised not to appeal to the IAS which is widely considered a kangaroo court, and almost certainly would be rejected, which will give them new impetus to pursue you even stronger and they might be buoyed by an IAS 'win' under their belt to brandish in case they issued.
If you do not pay, you will most likely receive letters by debt collectors or from the company themselves. The letters will be threatening and intimidating as their function is to scare you into paying. It is normal to receive these type of intimidating letters so expect them, but do not be intimidated by them.
The only way for them to get money from you, is for them to issue court proceedings. This is the only way for them to recover the funds. It is unlikely they will issue as it isn’t cost effective for them to do so, as the cost of court proceedings is more than what they can recover but some companies do issue and if this is the case, then you’ll need to ensure you defend the matter.
Given the circumstances you are likely to be successful if they do issue and they would have wasted their time. These claims are defendable with a high success rate. Worse case (and unlikely) scenario is they win at court , and in that event you’ll just be ordered to pay the original charge plus court fees which is about £25. If paid within 28 days it doesn’t appear on your credit file. But if you do not wish to go down this route, and want it over and done with, then you should pay them what they are asking for.
I hope this helps. Let me know if you have any further questions. Please also provide a rating. You can do this by clicking the stars at the top of the page. Thank you.