very disappointing

I am very disappointed. I contacted China search several weeks ago searching for particular plates. They kindly said they would put a search out for me, i even chased them after a couple of weeks but was told no luck as yet. I then found single plates on e bay both of which i brought as separate lots. At this point i didn’t even realise who was selling them. I purchased them separately as that’s how they were advertised and had to pay two lots of delivery charges of £6 each total £12. I cant help but feel this was deliberate selling them singly to make on the delivery charge and why wasnt I contacted that they had two why did i have to find them on ebay?