Hi Lizzie,
You'vve done very well, but please make sure you capitalise "I".
Mixed Tense Letters
Dear Sir,
I wrote to you three weeks ago, asking about conditions of entry into your college. You replied, enclosing an entry form, which I completed fell up and returned without delay. Since then, however, I haven't heard from you and I've have begun to wonder if my application has gone astray.
Could you please check that you have received it and if you haven't, please send me another application form.
If, on the other hand, you received my application but have not decided whether to accept me as a student or not, I would be very grateful if you would told tell me when I may expect to hear your decision.
Finally, if my application has been already was refused, I would like to be informed as soon as possible because if I am not don´t get accepted into your college I will have to apply to another and the sooner I do this, the better the chance I will have of being accepted.
Yours faithfully/sincerely,