Vectra 1.9cdti turbo problem

I have a 1.9cdti (150) vectra with 70000miles. The turbo has packed in
(according to my Vauxhall garage) and both it and the intercooler have to
be replaced.

I have been told that the turbo has filled with oil (caused by a leaking
seal). The garage have been told by Vauxhall that they MUST NOT fit the
new turbo without replacing something called the 'banjo bolt' (not sure if
this is correct spelling).

Can anyone tell me what a banjo bolt is? I suspect Vauxhall are aware of a
problem with this turbo but won't admit it. The car is under 3 yrs old but
because of the mileage Vauxhall won't cover this work (car has been fully
serviced at the Vauxhall garage).

Anyone had similar problems with this engine?