I've occasionally come across a fabric that just refuses to iron/press flat. There is just something about the way that it was manufactured that makes it stubborn.
If it bothers you now - what makes you think it won't bother you next year or five years from now?
Occasionally we get stuck/burned with something that is a dud. If possible, try to return it. If not, if you can - write it off as a learning experience - and I think most of us have had a few of those!!