Made mistake when purchasing TGV ticket online and can’t change or refund

What date is your ticket where you chose the wrong TGV station? Does the price of 22€ per person (?) show up on Trainline when you do a search for tickets that would officially complete your journey?

If a conductor is checking tickets after the Marne-la-Valée - Chessy stop, you aren't going to be able to show a valid ticket and will be fined. I wouldn't expect empathy. I don't believe they will care to listen to your plea that you mistakenly chose the wrong arrival station but if you'd chosen the right one, the price would have been the same. I don't know whether SNCF itself would be willing to revise your ticket but my assumption is that since you bought it from a ticket agent, Trainline, you're subject to their terms and conditions and that's who you have to work with. I'd just pay the 22€ to buy the ticket from Marne-la-Valée - Chessy to CDG. It would be worth it to me for the peace of mind of knowing that I'm not risking a fine, and to avoid the hassle of continuing to try to get ahold of someone who will empathize and fix the problem. I'd buy it now, before the price goes up.

https://support.thetrainline.com/en/support/solutions/articles/78000000458-exchanging-a-train-ticket-travel-outside-of-uk-

The wording is a bit confusing/contradictory ( at least to me)

General information about exchanges

Whether your ticket is exchangeable and whether fees may apply depends on the ticket booked and the relevant rail provider.
The departure and destination stations cannot be changed, only the departure time and the travel date.
Tickets should be changed before the original departure date.
Learn more about exchange terms for each carrier
France - including SNCF
SNCF
Most standard fares allow for exchanges.
Tickets can also be amended at a ticket machine or at the SNCF counter at the station

What kind of ticket you have may affect what can be done with it.

Yep, did similar. We sucked it up and paid extra. 22E is not that much.

Travel teaches us to check the tickets.

Enjoy your trip!!

I'd just book tickets from Disney to CDG. There's no need to change seats, it's unlikely the seats on your first leg will be used by someone else on the second leg.

I've done similar when I booked CDG to Saint Pierre des Corps, then had my plans changed, so I bought an extension (as it were) to Châtellerault.

You made a mistake, you may not like it, but now you need to pay the difference. The solution is easy, buy additional tickets to CDG.

Thank you all. I pre-booked my tickets for October. I immediately contacted Trainline right after I discovered the error. Too bad the tickets are non refundable. I thought since it’s so early, they could help me make the correction but there is no mercy. Anyway, I will purchase the extra leg.
Thanks!

In our case, we booked tix in France for a later trip, and got a discount. Our problem was that the French and US have different conventions for month and day. We used the wrong format. We got the wrong tickets. In our case, we did have refundable tickets, but by the time we discovered the error, we had to pay a higher amount. Oh well. We paid and lived to see another day.

I agree with Vickie. Buy the extra tickets and chalk it up as an "oh crap" moment that happens to us all.