Please correct my English letter.

如果只按照文法去改：
Guard of theThe Ccontrol Rroom of Queen's Building phoned us, and said that a worker was trappingtrapped in the balcony of his house. It was because he forgot to bring the key. Therefore, he asked for our help.
We Guard of the Control Room of Queen Building was informed the operations manager to borrowget the 後備 spare key from the property department at once, and then sentsend it to the guard of the mobile unit of the main building. Later the worker phoned us that he had been released himself from the balcony by himself. Andand did not need our help any more.

Control room並不是專有名詞，所以不要寫大楷。
Queen Building 有問題，因為Queen+甚麼字都會是要加上's，如:Queen's Road, Queen's Building, Queen's Pier.
He had been released by himself 的句式在文法上可算是正確，但在日常用法上是頗有問題。你的英文句可譯成中文的「他被他自己釋放了」；他是個清晰無誤的主詞，那麼若動詞用被動形，而驅使者又是他本人，這樣的句子就是把簡單事情複雜化，不乎合寫作要清晰、簡潔的目標。He had released himself就能簡單而清楚地表達同一個意思。

在文章大意上，我不明白以下的數點：
1/他是個工人（worker），為何會被反鎖在他房子的露台呢？
2/露台的門會這麼容易被鎖上麼？
3/他打電話到控制室求救，但在之後的一段，他又能夠自己把問題解決。那麼，為何他要求助？
4/文章中的我們（we）究竟是誰？在第一段中，我們不會是控制室或求救者。但在第二段，求救者向我們打電話和不需要我們的幫助。那麼，為何求救者起初又不直接向我們救助？

照估計這像一份事件報告。樓主先搞清楚：
Guard of the Control Room(不用提是guard，唔通有非護衛的人物在control room)
Queen Building ( Queen's Building 才合理)
worker was trapping in the balcony of his house.(既然是男的，domestic helper機會便不可能。那麼是何種worker呢？裝修工人才有機會拿到key)
property department 是指物業(發展)部定係大廈管理處Building Management Office ？管理處是入伙後的事。一般是沒有小業主的key。
試譯成下文：
The Control Room of Queen's Building reported to us that a worker was trapped in the balcony at his house due to no key in hand and ask for help.
We then instructed them to borrow the spare key from the Property Department at once by sending it to the mobile unit at its main building. However, the worker phoned us later for regrets that he was free already and discharged from the emergency call.
no key in hand 是解冇帶key在手，不用詳說原委
discharged from the emergency call 是消案
全文不提guard，唔通有非護衛的人物在control room or mobile unit。所以是大家都明的基本。

A Guard of the Control Room of Queen Building has phoned us and advised that a worker had been trapping in the balcony of Queen Building since the worker had forgotten to bring the key and he (?? he refer to the guard or the worker?) asked for our help.
The Guard was requested (<-- or you may use: instructed) to borrow the spare key from the property department at once and then sent it to the guard of the mobile unit of the main building. Later on, the worker phoned us that he had escaped from the balcony by himself and no need to have our help any more.