AutoNation Acura Gulf Freeway

I was pre-approved for a certain amount by my credit union. Talked to salesperson and we agreed on the price. Salesman was great, friendly, everything you could ask for. I informed him of my pre-approval and let him make copies of the certificate for them to fax all the information to my credit union. 3 weeks later no paperwork from my credit union in regards to my first payment. After calling around it turns out the dealership did not use my credit union, it was the last day of the month so instead they pulled my credit score with various other finance companies in order to get the sale through. Which in turn lowered my credit score by more than 50 points from all the companies pulling it to get it financed. Talked to the GM and he refused to help or even find out what or why that happened, instead just had a copy of the agreement and looked at me with a blank look and said "this is what you signed" and sat there with his arms crossed. Never bothered to ask his finance officer or salesman what happen. so now that i go back to my credit union to get it refinanced, my payments are higher due to my credit shooting down from Acura having it pulled so many times. really disappointing that my first vehicle purchase in over 12 years had to be like this.