If you don't want to return it, buy the 2.5" HDD/ SSD bracket and install the ssd into the hard drive bay, or using the tap to fix it inside the case.
I found there's a tray included for SSDs in the front bay, but Zalman didn't machine a screw hole on the front of the case meaning once that panel's removed it may never go back in place. If it does it will be on one screw. I used the dedicated SSD mount location. If you put one side in first, then screw in the other it fits perfect with the little the metal mounds filling up the screw holes on the other side. Thankfully I broke my Blu Ray player software disc, so the seller sent a new set of screws, cables and disc and I used those screws for the drive, because like the OP's there isn't enough clearance for Zalman's ones
The Z11 looks good, but does have a few problems with the stock fans. The dedicated SSD holder had me fooled for a while, but all you need to do is locate the bottom holes on the SSD over the 'bumps' in the lower brackets and the SSD locates easily, and then insert the top screws.
My problem was that I needed a SATA power cable extension to reach the SSD. Putting the SSD in a front bay wouldn't have needed an extension cable (for me).