I need help finding this replacement plate for my Gran!?

I bought the Coventry Modern Homes 16 piece Dinnerware (stoneware) plates in the Rosso pattern. It is a red center that fades out into this black that covers the edges and the bottoms. The over all finish is kinda spotted and it looks neat. However, one of the dinner plates was broken and I need a replacement desperately for my granny. I don't care about the cost, I just can't seem to find the set anywhere, let alone online. They are new so I don't want to get another set, I just want a replacement dinner plate! PLease help me!