Mercedes-Benz of South Bay

I took my Mercedes C240 for service to this place. I had a coupon in my email to receive 10% discount on total service cost. I gave the coupon to the service co-ordinator at the time while handing over the car. She accepted the coupon gladly. At evening I went to pickup the car and she directed me to accounts department where I paid more than $1400 for the service with an assumption that the coupon was used. But, later when I got home I took a close look at the statement and to my surprise the coupon was NOT used. Next day I called the lady and told the story and she said that she will look for the coupon in her office and let the a/c department know. After a week when I didn't hear anything from her I responded to the survay email from MB USA and mentioned the incident. After two weeks from then, I received a call from the same lady and she told me that she had found the coupon and accounts department is going to send me a check for the refund. I waited 1 month but nothing arrived in mail. I received a follow up call from MB USA asking about the issue, I told that they said to refund but didn't really refund a penny. The coupon is a bait-and-switch for new customers at "Mercedes of South Bay". I will never go or will never recommend someone to go there for service or for anything at all. Thanks Anurag Torrance CA