I am very sorry indeed to hear that you are not happy with the Poplin weave. Although the Poplin weave is one of lighter weaves and is more suitable for summer wear and for wearing under a suit jacket, I can assure you that it is indeed 100% cotton however it is a little more prone to creasing than our other weaves, simply due to the nature of the weave itself. Please see the following description from our website - "Poplin is a strong cotton due to its closely woven warp and weft threads, this produces a lighter feel that is Ideal for wearing under suits, and in summer." You can of course return this shirt to us for a full refund or an exchange for a Twill weave shirt if you are not entirely satisfied. I have arranged for a member of our Customer Support Team to contact so we can discuss this further.