So yesterday I find out that the owner of our company doesnt like to give specific job titles to staff members. I just started at the beg of Feb and was told I would be P/T Admin Asst. I'm now a little concerned that they'll start having me do things that weren't discussed in the job interview, such as personal errands. Another staff member has already complained about having to do this stuff. Has anyone else experienced this?

Would it be wrong for using this as a reason for leaving the company when I interview for positions elsewhere?
I dont want to bash the company Im currently working for but at the same time, I its a major deal breaker for me.