I started a job in January as a Project Coordinator for an electrical company. When I was hired, the position was advertised as "Admin Assistant", but after I was hired, the owner of the company said that he had advertised it as such because it was an entry-level job, and when he had advertised it under its actual title, he was getting overqualified applicants (like engineers). He assured me so confidently that I was exactly what he was looking for.
During my month there, I completed all my tasks successfully and never had any issues, other than the fact that the workload was a little slow, but that wasn't something under my control. When I was laid off this past week, my letter simply says "upon reviewing future requirements, we feel this is not the right fit". The owner said that I hadn't done anything wrong, and he agreed that I had fulfilled my duties successfully, but he said that "the last person in this job was an engineer" - which he originally said was what he didn't want! (So I feel a bit bait-and-switched). He also offered out of his own volition to give me a good reference for my job search.
So, I don't really have a clear reason for why I was let go, and I don't know how to explain that on my resume/cover letter. Should I just put "laid off" beside the job description on my resume, and include the owner's phone number as a reference? I'm just not sure how to explain this in upcoming job interviews.