Kindly check your credit card account. It is very likely that the reserved amount has again been released.
If you have not received an e-mail, and you are certain to have correctly entered the e-mail address, and it did not end up in the Spam folder, the transaction failed.
Transactions from Overseas often fail because people use credit cards which do not support the security standards for online shopping applicable in Europe. For a successful payment you should use a credit card that supports 3D secure.
In addition, today, the SBB were facing a technical problem with ticketing system. It could be another reason why the ticket purchase dis not work.
Do you wish to buy the Swiss Travel Pass? Should the problem with the purchase persist, you can buy the Swiss Travel Pass also from the Switzerlsnd Travel Center, STC:
The STC is a joint-venture of SBB and other Switzerland tourism companies. Passes bought with STC cannot be displayed in the SBB Mobile app, though.