Wiadomość e-mail - sprawdzenie

Temat przeniesiony do archwium.
Witam
Muszę napisać do jednej z amerykańskich firm wiadomość e-mail. Bardzo bym prosił o sprawdzenie błedów.

Cytat:
Dear Sir or Madam,
I passed final exam in April 2012 and I have finished the fourth semester "Accessing the WAN" to preparation for the 640-802 CCNA exam. Afterwards, I get discount voucher since I have completed the requirements for the one. My discount voucher will expire 12 months until the date final exam.
Now, I will to take 640-802 CCNA exam in the beginning April 2013, before the end of validity voucher, of course. Well it turns out that my voucher is not available. I see the message that says "This Certification Exam discount opportunity is no longer available. It was only accessible for 3 months and is now expired.". So please unlock my discount voucher according to expiration date that should the one available until the date I took my qualifying final exam.
I'm sending you the copy of your email message in attachment.

Sincerely,

Z góry dziękuję za pomoc.