Reference for sixth form college & sixthform school

Im in a very bad place right now I dont know what to actually do about this issue im facing. Basically I finished my GCSEs and I now I have an interest in going to sydney russell sixthform but i just wasnt able to apply on time .That is mainly because at that time my first mock exams was taking place no grades were given to me when asked for some and said grades will be revealed after exams marked and the deadline of application passed .Now I acc want to go sydney russell as my first choice but Im stressing so much they say no to me even if I have the grades required for subject.
Now, Ive been praying and making dua about this , and recently ive looked for a college and applied to new city college havering sixth form and they have accepted my application , as my backup choice.I dont acc want to go there because my mind is set on sydney russell and havering sixth form is very far .They have accepted my application and given me a reference form to complete by my secondary school head of year .

Now I was thinking, If I somehow give the reference form to my school to complete and give to the new city college and they receive it. The smallest chance sydney russell accepts me, what if they ask for reference as well from my school and the school declines it because they have already given a reference form bout me to another place at college.what happens then? Will there be any issue with me getting a place in sydney russell? I dont know ift they will accpet me so I also dont know if I should tell my school to complete the reference form to send to college.

Please HELP. thanks.