Hi. Some time ago I heard that the Dubai Outlet Mall had a shop that carried large sizes. I take 47 and have lots of trouble finding footwear. However I haven't needed to buy shoes yet in Dubai so I've not visited the mall. A quick search will find it on the web where you can see the floor plan and shops. But be aware that the mall is on the far outskirts of Dubai City and perhaps 20 Kms out. There may be public transport otherwise you will spend quite a bit on taxis.