There are steps to take before you spend more money on an attorney. Have you taken all of your paperwork, receipts, etc. and met with the general manager or/and finance manager of the dealership? Have someone go with you to take notes or ask to audio record the meeting. Show them the evidence and give them, in writing, a reasonable timeline of what you need them to do and when. If you have everything documented and reasonable requests, they should do the right thing if they don't want a lawsuit, bad publicity, and want a return customer.
As long as you are calm and professional with all documentation to support the facts, give them a chance to correct their mistake. Phone calls will not do anything; bringing issues up the chain will.
good luck