List formalny

Dear Mr Kowalski,
I am writing to complain about the pens which I purchased a month ago. I bought thirteen pens but I received only fifteen .
It is now three weeks since I received my packet, since then I have made numerous phone calls and I have sent numerous letters to your company headquarters and to date I did not receive any reply.
Because these pens are my very needed on my class. I would be grateful if you could look into the matter for my. If you not longer have the pens in stock please, refund my payment.
If you need to contact me I can be reached on 456456435613543515 or at my email addresses [email]
Than you in advance for your help. I look forward to hearing from you soon. Yours sincerely XYZ

Witam mam pytanie jak to jest napisane ? czy jest dużo błędów ?

>I bought thirteen pens but I received only fifteen .

Coś tu się nie zgadza: kupilem 13, a otrzymalem tylko 15?

>It is now three weeks since I received my packet, since then I have
>made numerous phone calls and I have sent numerous letters to your
>company headquarters and to date I did not receive any reply.

Za dluuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuugie. Rozbij to na przynajmniej 2 zdania.


>Because these pens are my very needed on my class. I would be
>grateful if you could look into the matter for my.

To powinno być chyba jedno zdanie, ale od "because" zaczynać zdanie nieladnie jest.
"Because these pens are my very needed on my class." Co autor mial tu na myśli?

If you not longer
>have the pens in stock please, refund my payment.
If you NO longer