Look under sound settings and make sure that call connect is unchecked. I am not 100% but I think that is the setting.
Look under call settings caller id readout should be thing only.
I don't know if you ever ended up finding out how to do it or not but I had the same issue and I fixed it by doing this:
Settings>Sound >Remove the check mark beside Roaming Tone
Thank you SO much! That was driving me crazy!!