1. Type up your main talking points, and ensure that the other party has this in front of him. Start the discussion, and say: “this time we are discussing my issues.” It may also help if the points you wish to discuss are written on the whiteboard, or backed up up with an email.
2. Show zero tolerance for deviation from your agenda. Deviation may be seen as weakness. Over time you can be flexible, but not until respect is established.
3. During the discussion, when the other side goes off on a tangent, tries to dominate or goes on and on, walk out the room or hang up. The other side will reconnect and upon doing so, you can say “this is time for my issues and you are overpowering me”. For YOU this may be rude behaviour but the other side will respect your behaviour.
4. If the above do not work, insist that a 3rd party be present in the discussion to facilitate. This is often extremely effective. Choose a party that both of you trust.