What a drama this turned out to be! Firstly, it transpired that I hadn't been charged the correct amount for postage which incurred a hefty fee from the Post Office. This was then followed by an unsuccessful delivery attempt afterwards.
My first trip to the Post Office yielded further unhappiness as they'd closed early to update their software. I was not a happy bunny.
Luckily, I was able to collect my parcel today and am all the more cautious about purchasing online. I'll be contacting the seller about my fee, as naturally I'm unhappy but I had a responsibility to check what I was paying when I bought this so shame on me too. Always read the small print folks!