that a deposit paid in respect of an intended purchase is not necessarily refundable, and Trading Standards have of course confirmed that, and also the fact that you don't have a cooling off period when you initiate a purchase contract. You have a period after receipt of the goods in which you may return them for a refund, but that's a different matter.
In this particular case however, it could be said that by agreeing (twice) to refund your money the shop had contracted to do so, albeit verbally. You may be on slightly thin ice, but nevertheless I think it's worth a letter (by special delivery, not recorded) saying that you expect the company to honour its verbal contract with you, and to refund your money - failing which you reserve the right to take further action to recover the funds without reference to them.
Then keep your fingers crossed.