Yes you're quite right plus the 7day cooling off period under the distance selling regulations starts from the day after the goods are delivered not from the day of the order.
Sounds to me like you have spoken to someone who doesn't have a clue what they are talking about.
I have just tried to read their terms and conditions and failed miserably, however I did get that they work within the laws of the UK and therefore you are due a refund.
There is an address in their t&I'd which you can write to giving them a week to issue your refund or you will take them to court, providing of course, it is worth it, initially it will cost you £25.