Let's see.  You took the vehicle in to the dealer with a legitimate problem
and were told to not worry about it.  Here's your options:

1.  Call the dealer and speak to the service manager.  Make it clear that
you intend to spend zero money there if they cannot demonstrate within the
warranty period that they're capable of fixing your vehicle.  My take:
"Failure to fix my vehicle within the warranty period is one thing, but
don't expect me to pay for this privilege."  This will be especially
effective if you've been a good customer at this dealer.

2.  Find another dealer who cares more about meeting their obligations
than being too busy with other work to car about actually putting effort
into finding and repairing your noise.

3.  Call Hyundai Customer Assistance (800-633-5151) and ask them why the
dealer is refusing to repair your vehicle.

I did , they told me not to worry about it.. but its loud enough that people
turn and look to see what the nosie is when ya go over a speed bump.. or
just entering or exiting the vehicle...

The noise is no more of a concern, but the advantage with an '06 is that
you can get it fixed for free.  If you don't like the noise, take it in.

my  06 Santa Fe does the same thing.... should it be a concern on a newer
vehicle????

Usually, this is caused by the rear trailing arm bushings.  If you can put
up with the noise, it's a non-issue.

I just had the rear shocks replaced on my 02 Santa Fe. Yet there is
still creaking coming from the rear going over bumps or dips in the
road.

Could it be suspension bushings, or maybe something else? I've spent a
lot recently on repairs, so hoping not to have to spend too much more!!

Thanks for any help offered.