I was trying to buy TGV train tickets from Paris Gare de Lyon to Aix en Provence on the SNCF website.but got redirected to Rail Europe when using the English translation. The Rail Europe prices are significantly higher. Keeping to the French pages, I found "Voyages-SNCF" much cheaper especially for IDTGV. The problem came in paying with a credit card. Niether my credit card nor my wife's card would be accepted. The same for debit cards.
We tried with and without middle initials and with and without spaces in the card numbers.
We are about 8 weeks out. Is this too early?
Any advice on using this website?
.

No, it's not too early. But unless you call your bank and tell them to expect international (French) charges, your card will be refused. And don't try to book tickets again until 24 hours have passed since the last time you tried.

It's your card companies' fault, I'll bet you anything. Did you even call your credit card company to ask if they blocked charges from SNCF? I'll bet they did. It doesn't have anything to do with your name. If you can read French, you can read the notices it gave you when the attempt failed (which probably said your bank wouldn't allow it), as well as the notice that you can't use the same card again for 24 hrs. I know because the same thing happened to me a couple weeks ago, but my CC company could "see" the charges and told me they blocked it, they could do that immediately, I called them just a couple minutes after it happened.

Thanks StCirq.
My bank has not received or blocked any transactions. I guess SNCF has trouble processing online.

I've never had a problem booking online, and have done it dozens and dozens of times over many years. I know others have had problems, though, so just keep trying. Or you can call the English-speaking number at 8 92 35 35 35 (dial 011-33 first).

StCirq,
Merci encore. I will call the number given.

You are not the only one. Plenty of threads on this site and TA.

I had the same problem. Called my CC company, etc.

Download SNCF app onto iphone or ipad - it is free. App is in french but easy to figure out. The only trick is using a French mobile number that starts with 06 and is 10 digits. I used the number of the apartment where we will be staying. A U.S. number will not work. Worked immediately. No problem. Bought 2 different tix with the app.

Don't ask me why their website won't accept our cards and the app does. I tried for weeks to buy on the website with no luck. Tried the app and magic happened.

Good luck!

If you plan to take an iDTGV train, you could see if you have better luck booking on that site:

http://www.idtgv.com/en/