Collectif Womenswear Jemima Rose Dance Swing Dress

I have another Jemima dress in a different colour and pattern but exact same dress.
The dress I already had was a size 18 and fit me when I was a size 16. Always have to size up with collectif. I'm now a size 18 so I ordered this new dress in a size 20. It came and it was huge on me! Sent it back and got a size 18 which was still baggy around my waiste! My waiste measures 40 inches and my bust 50inchs. Still a very lovely dress just a faf with collectif changing the sizing that IV been used to for so long. But I guess it's a good think they've finally made more true to size. Still love collectif.