I'm going through the exact same thing from training I did back in June. I contacted them numerous times and they either diverted my questions or ignored me.
So first I contacted Citizen Advice who told me what to do. First you have to send them a formal letter of complaint. You need to say exactly how they are in breach of contract and what you expect from them (Citizen Advice website have templates you can use). If you don't receive a reply, or a response that you are happy with, next step is contacting your bank. Once I sent the training company my complaint letter and they realised I wasn't going to leave it, they became very hostile towards me. Suddenly they got lawyers involved and the head of the company (who was extremely rude) took over correspondences. I must admit this was extremely unpleasant.
I contacted my bank for a chargeback in August (you only have a limited time to do this so be quick!). I had to provide all the evidence I had showing that I had tried to get a refund directly from the training company and I had to show them why I deserved my money back. They eventually gave me the refund, but unfortunately the training company has disputed it, and its STILL ongoing. Its caused me so much stress, and the company have lied and lied to try and get out of it, so I'm unsure if the money will be taken back off me.
If I don't get to keep the refund, the next step is small claims court. Only problem with this, is that if I lose then I have to pay all the fees, so I will be out of pocket even more.
Regardless of the outcome I will also be going to the company who accredit the course to complain and inform them that the course was a sham.
I really hope you get your refund, but to be honest, I've found the whole process extremely stressful. Best of luck!