PSA for those buying tshirt merch

Just came back from Melbourne n1 and it was amazinggggg. On the merch, I went to the last two tours down here and bought size small tshirts and decided to buy a medium for a slight more relaxed fit, but they’ve changed the merch company so medium fits like a large! (Same for my sister who brought an XL and it’s more like an XXL) Hope no one else makes the same mistake as me, it looks like the tshirt is wearing me :(