Did you apply for higher needs /top up funding?
Does the EHCP state that the student needs full time 1:1TA support?
I’ve had £12,600 for a student but this was to buy in 3hours/week specialist teacher support. The specialist came in twice a week and worked 1:1with the pupil and then liaised with his TA (not full time) re interventions and activities for the rest of the week. The money was also used for a whole staff Inset provided by the specialist teacher to up skill all staff with regards to the child’s barriers to learning.