Reklamacja poprawione

1.I am writing to complain about radio. I bought in your shop in London after 3 weeks ago. It is the newest model of SONY. Radio does not work. When I connected to power, the radio buzzed. The display shows the inscription: Error. Radio will not play CD. I do not know what happened. I must assure you that I am not to blame for what happened and I have not been trying to fix it. I want to express my strong dissatisfaction with this product. I would therefore be grateful if you could consider a full refund of £129.99 I hope you will give this matter your immediate attention. I look forward to hearing from you in the near future. My phone number is 123432.
Yours faithfully
XYZ

1.I am writing to complain about (a gdzie przedimek?) radio(.) dladczego tu jest kropka i koniec zdania, jak nastepne sie laczy z tym) I bought in your shop in London 'after' (nie rozumiem tego slowa tutaj) 3 weeks ago.
(a gdzie przedimek?) radio does not work. When I connected (ale co? siebie?) to (przedimek) power, the radio JUST buzzed.
I do not know what HAS happened.