Why Does June Chase Mastercard Invoice Have Aug 28 Transaction From Airfrance?

Chase will not allow a dispute on a transaction older than 3 mo. Chase said to contact Air France for a refund.  Chase said this is a rebill for a dispute from Aug.  We believe that the rebill should only be for $641.82 not 992.39.  On Aug 28 we booked 2 passengers for a flight with a connection that was impossible to make, we called Expedia to cancel and they assured us Air France would refund 100% of our fares. Chase removed the 2 fares from our Chase bill. A partial refund for the 2 passengers was issued.  Expedia said that they would have Air France issue the balance but Air France never did.  The original flight was $1342.96 each and the refund given was $992.39 each.  Chase only rebilled for one original $1342.96  and now they are rebilling us for $992.39.  We should be rebilled for $641.82. The difference is $350.57. To simplify; 8/28 $1342.96 charge 8/28  1342.96 charge 9/27  -1342.96 dispute credit issued by Chase 9/27  -1342.96 dispute credit issued by Chase 10/28 - 992.39 credit issued by Air France 10/28 - 992.39 credit issued by Air France 11/2  +1342.96 rebill by Chase 12/13 + 946.00 Air France charge 12/13 - 946.00 Air France credit 6/1    +992.39 Air France rebill __________________________ Total $350.57 We now are owed this credit from Air France Or if the last rebill of $992.39 is removed we will owe Air France $641.82.   We were dealing with Air France through Expedia.uk.  This was the original agent that booked the flights as we were stranded in Dublin during a hurricane. Could you help us have the $350.57 credit issued?  We have spent 10 months trying to get this correct. Thank you is advance. Brenda Alexander