<human>: Can you give me the gist of the text in a nutshell?

A few years ago I enquired about an IT course, was visited by a representative of the company, and 2 signatures later, was locked into a course with them. Fast forward to about last year when, after months of bad communication (the company changed hands at the peak of my difficulties) and general discontentment stemming from the fact I was being made to complete a hardware course before my desired learning, I wrote to them opting out.

Except I found out that signing the initial contract had locked me in, and my only option was to continue paying off the initial finance plan, which was about £6,000 but I'd paid off half of it by that point. 
Accepting that I'd lost £3k, I wrote back stressing that I was i no way going to continue the course, and that the severity of the contract had not been stressed to me during the casual first interview. I've since been told that not only must I continue paying, but the learning fees I paid only covered a 3 year period and now I must also start paying monthly fee's for not having completed the course.

The numbers aren't that important really. I wrote them a long and frank email informing them that I will never give them another penny. And that I feel like I've been scammed. I've moved away form the area and, yesterday, bailiffs were sent to my previous address where a friend still lives. He promptly explained that I'm not even in the country anymore (I'm not) and told them to fuck off. And has since assured me that my troubles are over.
How long can I expect this to go on? I do genuinely feel a bit robbed and, although I'm adamant that I'll never give them another penny and would rather go to jail/become bankrupt, it isn't THAT much money and I could techincally pay it off if I saved a bit.
<bot>: If you refuse to pay back a credit agreement, how long can/will they pursue you beyond a few letters and a bailiff visit.