I don't know for certain that they will have them but I would try Manias Home Collection in central Chania. If you walk up the western side of 1866 square from the top of Halidon and take the first side road on the right it is at the end of that road. I would guess they would have them either in the back right hand corner of the ground floor or in the basement. I suggest printing off an image of what you want, such as this one
, and show them what you are looking for. Stress that it doesn't have to be exactly that just similar. If you right click the image and select "copy image" you can then "paste" it into something like a Word document so you only print the image not the whole Amazon page. If they don't have them they might know somewhere else that does. I've always found them very helpful.
If you can't find one locally then Argos
are selling one for £3.49. I believe they will deliver to Nomad in Peterborough who will then ship to John the Butchers in Vamos with Crete Express