Originally Posted by
fly747first
How would a chargeback help in this case? Sounds like OP is upset (and with good reasons) that DL is demanding a fare difference to be in PS when he(s) originally booked PS. Doing a backcharge won't get the OP back in PS on a complimentary basis as Delta may opt to fully refund the ticket and the OP may still have to pay more money for a new ticket in PS.
If DL is demanding extra money for PS despite the passenger having purchased as PS ticket then simply pay the extra money and do a chargeback for that amount.
It worked for me years ago when DL downgraded me and then let me " upgrade " for a fee. The fare rules on my ticket were for first class so it worked for me.