Very un Happy

I bought a Telescope on the 24th November 2015, They sent an email confirming that they received the money, and confirmed that the item was in stock. They said it will be delivered on the 7th December. I go on to track my order on the 7th December, only to see that it is still to be processed. I phone them and get told they will look into it. Several hours later I call them back as I have heard noting, to be told by one of the agents that this item is no longer in stock, I then ask to be put through to a manager and get cut off. I go onto my emails and see an email from them, they do not have the courtesy to call me back, they email me that the item will arrive with them in 5-6 days, I then respond asking when will I get it. No response. On the 8th I open my emails to find an email stating that they are not going to get the item at all and apologise for the inconvenience caused, and proceed to say that they will refund me but it will take 2-3 working day to reflect in my account. I do not accept this. They have had my money for 15 days and want and immediate payment done, and I want the interest that I have lost. I cant even give you one name, as I have had multiple people reply.