Right... update.
They've responded, and are going to refund the full amount (I just have to phone them up to sort this out). In terms of the court case, apparently they have to attend and withdraw the case in person on the day of the hearing. I'm not quite sure as to why this is the necessary route, but there's no mention of my presence being required, so we'll just let things play out I suppose.
Thanks for the help everyone, and I hope that this thread might help for others in a similar situation to me!