Free Traffic Legal Advice

I have been advised to come here from reddit.

To start with, I am 100% to blame for this. I am looking if there is anything I can do.

Two months ago I received a letter from NPC (national parking control) for leaving with out paying in a car park near town (I had no clue that there were parking restrictions in that area so I used to park there often). The first letter i received said I need to pay £100 pounds. Me being new in this country, new driver and not having much knowledge about parking and stuff, I ignored it.

The following days I kept receiving letters from NPC. In total I received five letters from them. I thought all the letters were for the same incident and they were just putting pressure on me to pay the £100. So I didn’t check the letter much and put them aside (stupid mistake I know).

Long story short I decided to pay the £100 so I went to the NPC website, entered my reference number from the first letter I received, and paid the £100 amount. All done.

Few days later I received a letter from another firm called DCBL.The letter says I need to pay £170 debt for unpaid parking charge. I phoned them straight away and told them that I have already paid the £100 fine to NCP so I don’t need to pay them. They asked me to email them the receipt and I did.
They kept sending me the same letter the following days but i ignored all thinking its same thing happening again. They sent me four in total.

It turns out to be those five letters at the start were from different incidents. As I paid one to NCP, the rest 4 were transferred to DCBL.
Now DCBL are asking me to pay £170 for each of the 4. That’s like £680 in total. Plus the £100 I already paid becomes £780. I phoned NCP and they said they don’t have anything to do it with it now and I have to deal with DCBL.

DCBL are threatening to take me to court if i don’t pay them. I am student doing small part time jobs to make a living. I am not capable of paying that amount of money.

What can I do? Thank you.