Incoming call issues

My phone rings for 5 seconds only, although I configured it for 15 seconds
We cannot control how much time it takes your operator to effectively forward the call to your mobile phone. This depends from operator to operator and may ...
Fri, 25 Aug, 2017 at 7:45 PM
How do I disable my second line so that incoming calls are forwarded to my colleague when I'm busy?
Contact your mobile provider to find out how to disable concurrent calls. 
Wed, 9 Aug, 2017 at 9:28 AM