I need a small on top and a large on the bottom. How do we order this way?

Je viens de recevoir le maillot de bain en taille M , ma taille habituelle … beaucoup trop grand ; sans doute une mauvaise série vue les commentaires précédents , mais déçue
J espère pouvoir l échanger sans frais pour la taille inférieure
A suivre donc

I have a question. How can I order the top in one size and the top in a different size?

Shipping was fast but unfortunately the S is too big for me. I am 100 lb, 5’2”.

I originally bought a xl based on the recommendation and it was very roomy, too big in the chest. I returned it and bought a large and it fit perfectly. It is very flattering and comfortable.