Sorry, I've got the wrong number.
对不起，我记错号码了。
A Hello, can I speak to Mr Li, please?
A 你好！请问李先生在吗？
B I'm sorry. Who do you want to speak to?
B 对不起。您找哪位？
A Mr Li, the Marketing Director.
A 李先生，市场部经理。
B There's no Mr Li here. This is a private number.
B 这里没有李先生。这是私人电话。
A Sorry, I've got the wrong number.
A 对不起，我记错号码了。
B That's OK, Goodbye.
B 没关系。再见！

Notes注释
1 It's very easy to dial a wrong number. To apologise for getting a wrong number, you can say: Sorry, I've got the wrong number. / Sorry, I've got the wrong number.
很容易拨错号码。当为拨错号码而道歉时说：Sorry, I've got the wrong number. /对不起，我记错号码了。
2 If you receive a misdialled call, for example, a business call for someone you don't know at your private number, you can say: There's no Mr Li here. / There's no Mr Li here; This is a private number. / This is a private number.
如果你接到了打错的电话，例如，一个打到你的私人电话上找你不认识的人的商务电话，你可以说：There's no Mr Li here. /这里没有李先生； This is a private number. /这是私人电话。

Key phrases and sentences
Hello, can I speak to Mr Li, please?
I'm sorry.
Who do you want to speak to?
Mr Li, the Marketing Director.
There's no Mr Li here. This is a private number.
Sorry, I've got the wrong number.
That's OK, Goodbye.

你好！请问李先生在吗？
对不起。您找哪位？
李先生，市场部经理。
这里没有李先生。这是私人电话。
对不起，我记错号码了。
没关系。再见！