請幫忙翻譯為英文, very 急

我唔小心 join 了一個Consturct data "Advertisement entry Fair-Guide" 現在要付款才知弄錯, 想取消, 但應如何向他們解釋呢? 謝謝幫忙應如何回覆.
好急的. 謝謝
請直接和有關機構聯絡及說明你的要求. 下面是根據你上文的意思翻譯成英文及加了一句英文不太好, 才弄錯o


Dear Sir/Madam,

My English is not so good so I have mistakenly joined a construct date "advertisement entry fiar gude" I realize it is not a free entry when I am requested to pay.
I would like to cancel my subscription effective immediately.

Thanks and look forward to having your acknowledgement to this request.

Yours sincerely,

XXXXXXX

.I'm not careful join a Consturct data "Advertisement entry Fair-Guide" now, we know the right to payment, to cancel, but how should it be explained to them? Thank you for help on how to reply.

我推薦您一個非常不錯的英語學習網站，里面有很多非常不錯的學習資源：

http://www.hkenglishstudy.info

希望可以幫到你!

我唔小心 join 了一個Consturct data "Advertisement entry Fair-Guide" 現在要付款才知弄錯, 想取消, 但應如何向他們解釋呢? 謝謝幫忙應如何回覆.
好急的. 謝謝

I'm not careful join a Consturct data "Advertisement entry Fair-Guide" now,we kknow the right to payment, to cancel,but how should it be explained to them? Thank you for help on how to reply.

Better hurry. Thank you