I called them and told them I was going to be 10 m...

I called them and told them I was going to be 10 minutes late and asked if they could still see me. They said that s fine, so I went ahead and continued driving. Arrived, after waiting for another ten minutes I was told I needed to reschedule because I was a half an hour late. Umm, no? I was ten minutes late and ya ll said that was fine. I just need help.