There was no clear size info and we bought it considering as one-size-fits-all, but it is too small for my foot size (41). Can't use it any more.
Thanks for taking the time to write to us,
As mentioned by you regarding the sizes. The sizes are clearly mentioned right below the size guide beside the product image as ( UK 8.5 -11, UK 5.5 -8 and UK 2.5 -5) You should have selected the size as per your shoes size to get the right size.
In your case if the product is sealed and is in resalable condition, you can visit to your nearest Decathlon store and get it replaced.
Hope I was able to solve your concern, For further assistance please feel free to write back to us.
Jagadish YADAV DECATHLON