One thing these scumbags definitely don't issue is "fines", in quotation marks or otherwise. Only the police or government can fine you for parking. It's a Penalty Charge Notice from the council, I think the police one is called something different. These guys aren't allowed to use the word penalty, as that would be fraudently pretending to be a fine. But Parking also begins with P, and any invoice can be a charge notice, hence parking charge notice (PCN) being so suspiciously similar. Often they even go to the trouble of making the tops of their letters stripey to look more official.
They are invoices. They are invoicing you for parking. There are various legalities that make a lot of them challengable, but in most cases they're only allowed to charge you a reasonable amount. So if it would have cost £2 an hour to park, and you over-stay by an hour, then they can invoice you for £2 + a reasonable admin fee. Not £120. So it's basically a highly speculative invoice.
They even then follow them up with fake debt collection letters. Given that they often have a trading name that's a 4-surnames-in-a-legal-sounding-row type. So they'll chase you up on behalf of, when it's actually the same company, or at least the same people running it.
There's a whole bunch of info on how to avoid paying these wankers on the excellent Money Saving Expert site: linky.
The DVLA should at least use this opportunity to say no more data for you wankers, as you lost the last lot, and put them out of business. Then legislation should sort them all out.
On the other hand, people also need to stop taking the piss and parking on private land. I used to work for a shop that had a small carpark, which was free for customers. And some people would try to park in there and go to work. Which isn't acceptable behaviour either.