Complex sentence: From 1999 until 2004, and during 2007-2008, Pakistan was suspended from the Commonwealth of Nations; during those periods, India and Pakistan exchanged Ambassadors instead of High Commissioners.
Split into simpler sentences: From 1999 until 2004, and during 2007-2008, Pakistan was suspended from the Commonwealth of Nations. During those periods, India and Pakistan exchanged Ambassadors instead of High Commissioners.