What to do if you're not happy with the support you're getting
As you know, it's best to try to solve things directly with your SENCO first - setting out your concerns and asking for their agreement to make improvements. If this doesn't work, you might want to then escalate your concern either to your head of year or headteacher.
At some schools, the headteacher is also the SENCO. If this is your situation, or if you have escalated your concerns to your headteacher and this hasn't worked, you could then write to your schools lead Governor for SEN. Every school has one, and you can find out on your school's website how to contact them.
Visit SENDIASS' website