Cintas Sale Representative interview questions

The process began with a short phone interview with HR. First in-person interview with the Sales Manager went well, I went on a half-day ride along the next week where we cold-called and he told me about the day to day, then two more interviews in the following weeks. I was called and told that I was being offered the position at the end of the 4th week contingent on a reference check, background check and drug screening. I completed my references via an online form. Now I'm just waiting... The ball is in their court. It's now been almost 7 weeks since my first phone interview and HR and the manager has not responded to my calls or emails for the next steps. Very unprofessional and I'm hesitatant to accept the offer if they decide to hire me.