"Has got so bad I am now changing to a different..."

I have been with this practice for over 10 years. I have found it increasingly difficult to get in to see a doctor or other healthcare professional and I am extremely dissatisfied with their overall policy towards sick children. My child is very ill again and has not been seen or even had a call back and it is Friday. Have called over and over trying to get my child seen before the weekend. This is his third weekend suffering from gastro and they're just not interested. I am making a formal complaint about their standards in practice.