Oh no, it's worse than you think. They don't want to hire me at all, because they style themselves as a training company which has a dedicated recruitment team who when not harassing people like me use the same recruitment agencies that anyone else with a computer and Internet connection can use to put people forward for jobs. So there is no job, only a promise from them that if you don't have a job within six months (note job, not job in IT or other field vaguely relevant to the certifications you've shelled out for) they'll refund your course fees.
You're right in that this is an unusual hiring practice in the UK and I'm not entirely sure why the otherwise reputable recruitment agency that this company must have mined my details from allows this company to do this (or why they are allowed to advertise "jobs" on the agency's website with descriptions that state that candidates would be expected to pay for their own further training). I believe that the company is misleading people but I'm not sure what recourse I could take if any, primarily because I don't know enough about the company as the telephone conversation this morning was the only contact we have had and hopefully ever will have (in other words, no harm done). I do find it strange though that I haven't found or heard any negative experiences about it other than what Matt and I experienced.
Rest assured, my original question was not whether or not to get a certification from this training company (when they first contacted me this morning I hung up as soon as they introduced themselves - besides, if I had £8,000 to burn I wouldn't be desperately looking for a job nor applying for full-time work at a fast food restaurant) but more about what I should do in terms of gaining some experience prior to graduating from University and whether some type of certification would be advantageous in this endeavour.