Taking the name doctor in vain

On Monday I bought a bed from the RC and the Willey. It is a REAAAL NIIICE Cal-King and it was delivered today. The only problem is that they were supposed to deliver 2 boxsprings for it, but they only delivered one thanks to the lame salesman at the RC and the Willey who didn't know what he was doing. I called him and he told me that I was going to have to pay another 200 bucks for the second half of the foundation for the bed. I told him, "I can't believe you are doing this to me. I am a doctor and I can't be wasting my time waiting for my mattress to arrive and dealing with your mistakes." He called me right back and said that his manager was giving me the other 200 dollar boxspring for free. I feel bad for whipping out the doctor title, but if it works, why not?