How do I fit a new kitchen mixer tap, New kithen installation ?

Having purchased a new kitchen and intalled most of it I am having a problem with the monobloc mixer tap. The tap supplied is proving difficult to fit due to the flexible connecting pipes won't fit past the fittings that support the tap. The recess in the base of the tap is preventing a normal spanner tightening the flexible connecting pipes. The tap was supplied by Rock Solid Kitchens but the box it came in has no makers name on it. This is one of a lot of items supplied that have given me problems but I didn't expect the tap problem.