Got it
It was a simple solution. If you have this service to transfer calls either if you are talking while you are talking, usaliy transferred to your voicemail, instead disconnect that. When you hear incoming call look at the display and precess ignore button and you will transfer the call. This can also make the incoming call go directly to your voicemail without any loony ringing. All of this of course dependes on what services you are offered from your vender.
Works fine for me🙂