Originally Posted by
sexykitten7
I would send all my receipts to Customer Care and write "My roundtrip [PNR1, $] was erroneously canceled and refunded by United mid-journey, which necessitated the purchase of a walk up fare [PNR2, $] for the return segments. Please issue a partial refund [PNR2, $] for the difference."
If they don't respond, contact Oscar.
Assuming you had to buy your new seats on UA, this is exactly how to address this. But if UA does not respond initially, I would also file what you send to the executive office with DOT. If you had to re-buy more expensive tickets with UA, due to UA's mistake, then its effectively a post sale price increase, which is illegal.
Note, if your flights back were not with UA, then its sticker...