Following the letter of the law, you are responsible for payments to said finance companies for the duration of the loan you signed for (even if you didn't realise what you were signing up for). There is a lot of unfairness going on but then the law, supposedly about fairness, often isn't fair. Some retailers have chosen to default on payments, some have given up their machines (but remain stuck in the contract, unfortunately) and others have moved on to other systems suppliers to keep their Infotec machines in working order.
Some retailers don't care if they get a black mark on their credit record (so far none of the finance companies has actually made good the threat of court). For some traders a black mark would be 'coals to Newcastle' anyway. Others care a great deal. You can always check your credit record if you are concerned. If you note the aforementioned black mark, you can also write to the main two operators (Experian and Equifax) and add a notice of correction at a nominal cost to say that this particular account is in dispute. You could name the supplier, say that the equipment is faulty and that you are holding all parties in breach of contract.
As a point of interest, if you search Lanwall Services and/or Lanwall Systems at Companies House, you will see there are proposals to strike the companies off so these finance companies need to find a solution soon.