If you can't return it don't loose heart as the basics of the kit are ok to start with.
It's also supplied from
www.overclockershideout.com and I'm also using the Copper block that comes with that kit. Although it doesn't incorporate a built in hold down like the Maze 2 it has bigger & better water channel CNC'ing. The Maze 2 didn't exist back then, (and I think it has recently been improved in the water channel area as well).
The OCH block is very big and works well. It also has a lid that is attached by screws. This enabled me to take it apart and measure the base thickness. It was 4.6mm, too thick IMO so I carefully milled it down to 1mm, (very thin), and this gave 6°C max CPU load temp reduction with the same wateflow and temp.