Can a merchant charge my account after more than a month?

I had my hair done in March as a birthday gift for myself. I was charged for it in June. When I found out about the charge it had already caused me to overdraft on my account. I thought that my identity was stolen and I had called the police! It was the police that found out that due to a technical error they were just now charging my account. There was no warning on my part! I honestly dont think that this is ethical on their part.