Thanks to all who have offered me support. I wanted you to know with that advert has now gone out for a new full-time TA for DS. TA is no longer working with DS.
I'm working with school to support DS in the meantime. He is a complex chap and I'm in no rush to grab at any passing TA to support him.
It has been a difficult situation as this school doesn't use TAs it uses teachers to teach and so it hasn't been as simple as swapping him and it would be infantile to think the TA could be sacked for being unsuitable. There was no way I was moving my child from a school he likes.
It has all worked out in the end.
Thanks.