Wow, that is an insane policy. Surely your ticket is from point 'A' to point 'B' with the airline or alliance/group, and as they couldn't provide a reasonable connection a layover was required. To then recharge you for your luggage to complete the journey and at a higher international rate is bewildering to me. What a customer unfriendly policy! Was this pointed out clearly to you before you paid for the ticket and baggage charges ? If not, you might well have a case for compensation of some kind.