Whoever told you 6-8 weeks was wrong. Dealers were instructed to tell special order customers that they could wait up to 16 weeks.
Mine came in at around 10.
Get the Vehicle Order Number (VON) from your dealer, then contact Jeep Cares from the Jeep.com website either online chat or phone, provide them your VON and any additional information to identify yourself and they'll tell you what the status is.
If your dealer doesn't have a VON available, then I hate to break it to you, but your Jeep order didn't get submitted by the dealer.