"out of hours doctors appointment"

I needed an out of hours doctors appointment as my GP's surgery had made an error with my prescription (which is ordered and collected by Boots the chemist). I rang the out of hours line at approximately 3:30pm on a Saturday and asked for an appointment. The lady that answered told me that the next available appointment was at 7pm which was not convenient for me. When I told the lady it was not convenient for me, her response was "well you should have rung earlier".

I thought that this was very rude as I had only just found out that there was a problem with my prescription. If I had known earlier, I would have rung earlier! I was very annoyed that this woman spoke to me as though the situation was my fault when it was my GP's surgery that had made the error that lead me to need an out of hours appointment.