Hi Tamdolan, I replaced one of those on my previous car, Sportage, going to the same store tomorrow to see if they have one that fit Ceed... If yes, I'll post the dimensions.
Me being in Sweden doesn't help you much with the store's name, but if you really can't find them, how about replacing only rubber? Buy the rubber or the cheapest wiper for the front, take the rubber out, cut it and insert it in your rear wiper...
infosgpetch.co.uk Rear Wiper Arm and Blade regularly
£13.38 now £12.04 +vat and shipping. I just went to Hafords and bought a pack of wiper refills and cut so size. If you measure your blade you can buy the longer refills and get 2-4 refills from it. It is easy to slide the rubber blade out and back in and easy enogh to cut with a razor blade or good pair of scissors. I paid 9.00 for the smaller refill pack of 3 as they didn't have the longer ones at the time. Your details do not say where you are, so don't know if you are in the UK or not nor what model you own