Urgent help needed

Ok a lot of deadlines are coming up hence the title-I want to resit A Level Maths chem and bio. I want to be able to choose my own exam boards and also get predicted grades and also be assigned an exam centre where I can go sit my exams. Can anyone reccomend any websites or colleges (in or near London) wher this can be done?

https://oxbridgehomelearning.uk/courses/a-level-courses/?utm_medium=ppc&utm_source=adwords&utm_campaign=Category+-+A-levels+%5BExact%5D&utm_term=take%20a%20levels%20privately&gclid=Cj0KCQjwgNanBhDUARIsAAeIcAvYF0eeoZnMi1fO4Eu9-qHIVQQhr0THirdMOZWR-X1wDWdWwbT7R8MaAgFoEALw_wcB

From https://oxbridgehomelearning.uk/why-students-love-oxbridge/
‘Securing an exam seat can be difficult! We provide a guaranteed space in one of our partner exam centres around the UK.
They do one year fast track A Level courses’