Is your size chart accurate? I ordered 2 men's pajamas (S65-U08407 &S65-U08406) in medium. My size dimensions are: sleeve 32, waist 34, & chest 40. I opened and wore 1 set which was way too large (the waist actually measured 42" and the sleeve covered my knuckles, being 2-1/2 too long). I am returning the unopened 2nd set to exchange for small . My question is: can I open and try on the exchange to see if it is too small and still have it considered to be in the"original condition" eligible for a return?