Mazda of Clear Lake Mazda-Volvo of Clear Lake ,Did not honor quote, Webster, Texas

I contact Mazda of Clear Lake located in Webster , Texas (20101 Gulf Freeway, Webster , Texas , 77598 ) via email in order to obtain a price quote for a 2010 Mazda 6. When I arrived at the dealership, they said they could not honor the email quote saying that it was a mistake. They were willing to sell it to me for an extra $980. When I refused and walked out, the sales associate followed me out and said they would meet the price they quoted. When I arrived the next day to sign the paperwork, they said they could no longer meet the price because I did not meet the owner loyalty $500 rebate (even though I was told the evening before that I did). Therefore, the price to leave with the car had increased $500.  I did not purchase the car since they refused to sell it at the price we agreed upon twice. I believe the tactics used were underhanded and borderline illegal (i.e. bait and switch).