Don't be put off if you are told there is a waiting list for a service you want to access. Make sure you're put on the waiting list and ring regularly to find out what is happening with your request. Otherwise you are invisible and may be forgotten. Keep a written record of who you have spoken to, what they told you and the dates of each phone call. You may have to refer back to this in the future.
Most services have a range of official quality standards they are supposed to meet.
You may like to ask your service provider how they measure and monitor their quality of service. It may be helpful to have a brief written summary of your family situation, including your child's history of involvement with services. Ideally, you can keep the summary on computer and update it for on-going use. The summary will save time and allow you and others to concentrate on dealing with the specific issues at hand. Be clear about what you want.