Oh dear woowiss I can feel your frustration from here!
You're right that each child is entitled to free nursery education from the term following their third birthday, however each LA sets their own conditions attached to the way the funding is administered and is entitled to remove settings from their list of registered providers. Similarly there are no hard and fast rules that I am aware of that say how many times an advisory teacher should visit to offer support. In our local authority the early years team has been reshuffled and we no longer receive visits from advisory teachers.
I do know that there are advisory teachers on here who will be able to talk about their perception of their job and how it works in their Local Authority - I'm sure someone will come forward with advice and encouragement!
The Local Authority has a duty to ensure there is sufficient, high quality provision to meet local demand for childcare and as such they have a responsibility for improving quality in the setttings they support. It sounds as if you're having a rough time - is there any higher person in your Authority who you can turn to for help?
What kind of setting are you? Are you a member of the Pre-school Learning Alliance or the National Day Nurseries Association - if so maybe they can offer support and advice about where you can go now.
Sorry I can't offer more help.
Maz