Hello, I want to buy KOCCI Zra Model New Season Comfortable Fit Men's Short Cashmere Coat Jacket Coat, but i don’t know which size to choose. Mostly i wear S because i like my clothes to be fit for example i wear OVS, SELECTED AND JACK&JONES- S size but when i asked AI it said to buy size M because the fabric is 100% polyester and it’s not gonna stretch also AI said because ur company doesn’t got size XS it means S could be small. I am so lost at this point and i would like to get help from you. My size chart- Height-1.81-82 cm. age-18. Weight-62-64.