You need to look at the error code you get in the URL after a login attempt. If login fails, you will be redirected to a page which as an URL similar to this: mysite.com/?provider=QQ&code=5
Below there is a list of error code and their associated description.
0 : Unspecified error.
1 : Hybriauth configuration error.
2 : Provider not properly configured.
3 : Unknown or disabled provider.
4 : Missing provider application credentials.
5 : Authentification failed. The user has canceled the authentication or the provider refused the connection.
6 : User profile request failed. Most likely the user is not connected to the provider and he should authenticate again.
7 : User not connected to the provider.
8 : Provider does not support this feature.
If you get error code 4, then most likely you did not enter the keys in the admin page. If you get 5, then double check to see the keys are correct and your application is correctly configured on http://open.t.qq.com/development/
Let me know if you manage to get it working.