Satin Corset

I ordered the black model "satin" (90% Polyester, 10% Spandex), item arrived today 7mars instead of March 11, so pleasant surprise especially since I live in Guadeloupe. FYI this is an item made in China, but shipped Netherlands.
A good quality product that looks like the photo.

The only problem was that I was a bit lost for choice of size at the beginning when my order I chose M by referring (in error) to the corset size guide Latex.

In checking my order I noticed there was a different size guide for the satin model and there according to my measurements (in cm) XL was needed, so I quickly contacted the seller was very responsive and change my order before shipping.

Result corset in "too much" for my height it did not at all sheathing or slimming effect expected, I attach it to the last stop smoothly.
Results of the accounts I still do not know what size it should have been taken? Maybe 1 or 2 sizes below my waist as Amazon calls? I'd like to order another one, but I am lost ...

PS: there are no string comes with this model.

EDIT 03/14/15: I contacted the seller to report that the XL was too big, he replied right away, he sends me another FREE satin corset (size M). Too happy. For those who hesitate taking your usual size (S, M, L or XL) and if it will not contact the seller. And considering the price you have nothing to lose. (I put them blow their 5th star, BRAVO)