"4 month baby injections"

We took our baby girl to the GP to have her 4 month injection. A few hours later, we got a call from one of the nurses in attendance so say that they has in fact given my daughter the injection for the 12 month. So she had got extra of one. They said not to worry, just to expect some localised pain in her leg. Well, she has been so off, feeding erratic, crying, and now a rash has appeared across her back. It’s very upsetting. How can two nurses check and sign my daughters red book, to say that correct medication was given, then later say it was wrong? She is starting to get back to her normal self after two weeks, she had no reactions with her other injections either...