20 week scan

So I went for my 20 week scan 2 days ago I couldn't find out the sex of the baby as baby was laying in a awkward position the sonagrapher wouldn't try anything to get the baby to move she just said cannot tell you the sex I asked her if she could try something she said no and that I have to get a private scan that's not fair at all I told her from the beginning I wanted to know the sex I shouldn't have to go private she should have booked me another appointment shouldnt she ? I am so annoyed what do I do?