There's perhaps three obvious solutions, none of which is ideal.
1) You remove the RAM heatsinks (as I assume that is what is clipping with the H100i). They are generally pretty decorative and unnecessary. If you have a common brand of memory then it's likely there's a guide online showing how to do this.
2) You mount the H100i rad inside the case and the fans for it on the roof of your case. This is fairly impractical for most people.
3) The top section supports two 140mm fans, so there's clearly some space to move the cooler around. If you can drill some mounting points in the mesh (a washer or something should support these) and some offset slightly into the frame you might be able to fit it in without effecting the performance significantly.
If none of these are options, I'd consider trying to return either the memory, motherboard, case or cooler as it's likely by changing even one of these you can probably get things in.