My childs class teacher is being really awful to my child?

My daughter is 10 years old and always tried really hard at school. We have never had a complaint about her behaviour. We requested the school screen her for dyslexia when she was 7 and she came out as being high risk. The school did nothing to support her - we have been in and spoken to the deputy head and SENco about our concerns, but to no avail. The school will not provide any support or send her for the full assessment - even though they acknowledge that she has problems. She was re-screened recently and again came out as high risk. Her teacher calls her lazy and tells her that her handwriting isnt neat enough to write with a pen so she is made to write with a pencil - even though none of the other kids do. Please advise as I keep going to the school and they keep fobbing me off. It breaks my heart to see my happy, confident daughter having her self esteem bashed. Thank you for any advice or suggestions.