I wouldn't use it as it is! The vibration from the pump is likely to cause more problems, i.e I can see that chunk to the right falling right off.
To me it looks like it's taken a knock, under tension from the screws (probably overdone) .... crack
2 options,
a) return as damaged
(or personally I would, if I couldn't wait and wasn't busy)
b) get some perspex adhesive from diy store, carefully remove the pump and fill gaps with adhesive, small chunks at a time (don't go blobbing it all over), apply a little, let it dry, apply some more etc.. until you are confident you have good bond