[Clipper]

My Entrance tile was also a little bent when I got it, but it did flatten out with a little reverse force, thankfully.

Note that if it's a problem of the links not connecting, sometimes it's better to try connecting links to tiles from the other direction (link on tile or tile on link). I can't think of much else to help with true bowing of the tiles apart from what you've already tried to do, though.