Under mount installation granite countertop

I had granite counter tops and a under mount granite sink installed by a
"professional" granite company in Kalamazoo Michigan. Everything was ordered
from them, granite, sink, fixtures. We wanted the sink edge to be completely
under the countertop. It was installed by one man using a 2x4 held in place
with one old bungee cord he found in our garage. The cord broke after about
one hour. He applied a bead of silicon around the top of the sink before
attaching the old bungee cord. There are no other supports used to hold the
sink in place. I am not sure that it will hold when the sink's weight and a
sink full of water is added together. In addition, some of the sink's top or
edge is completely under the counter, some flush with the opening and some
sticking out from the opening by 1/4 - 1/2 inches. The holes drilled in the
granite for the faucet/soap/sprayer do not match the pre-drilled holes in
the sink by 1/2 to 1 inch which they corrected by routing away part of the
sink itself.
In your professional opinion is this an acceptable industry standard for
workmenship. I can't get the contractor to even discuss the problems. His
only comment has been "he cut according to sink manufacturer's template". It
just seems the actual installation process was bad even if he did cut to
specs (which was not what we wanted).
Thank you in advance for your response,
Bob Risenhoover