DHL interview questions

I applied for the position through their website and received a phone call approximately two weeks later to come in to complete a written exam, typing test and data entry test. I asked about the salary range, but the HR Rep said she did not have that information. I was told if I passed the written exam, I would move onto the typing and data entry tests and then I would be interviewed. The written exam had 50 questions in the area of math, grammar, language and logic. I only had 12 minutes to take it and it's expected that anyone taking it will not finish all 50 questions in 12 minutes. I passed and went onto the other tests and then the interview (they did not tell me how I did on any of the tests). The interview was basic, typical interview questions (give an example when you disagreed with a supervisor and how you handled it.... give an example of when you did not get along with a co-worker and how you handled it... describe yourself in three words... etc.). It lasted about 30-45 minutes. I asked the interviewer about the salary and he said that HR reviews your prior work history and decides what to offer and he could not tell me. At the end of the interview he asked that I go get a drug test completed, that the company would do a background check and if everything came back good, I would receive a job offer via email the following week. I interviewed on a Wed., and received a job offer a week and a half later. In my on-line application, I put my min. salary requirement as $40,000 and on my written application (that they had me complete prior to the testing) I put the same amount. Even though I was not told the salary range, I figured the offer would be somewhat within the min. requirement I listed. I WAS WRONG!!! The job offer was for $12.00 an hour. I declined the job. I'm not sure why they even bothered to interview me when I had such a high salary listed?!?!!!!