I purchased 2 of these dog beds in medium. The dimensions on the website  is 50cm Wide x 50cm deep . The actual width of the item I received was 40cm deep and that’s being generous. Both items are labelled medium.
I spoke to Wayfair Customer Services last Wednesday morning (eventful) and explained the issue. 
I was sent an email link to attach photos of the items to  and was told that  once received, the issue would be looked into and resolved. 
On Saturday morning DHL delivered 2 replacement items and guess  what ..they were exactly the same size ..10 cm short on the advertised depth.
The dog beds look nice and they seem reasonable quality ,however, if the sizing is totally incorrect, they are not fit for purpose and are being  falsely advertised.