Can I reverse or cancel a transaction?

Once a transaction has been successfully completed, it cannot be reversed or canceled. This is true for all coins/tokens used in Jaxx. The only way to "reverse" the transaction would be to send the funds back from the receiving wallet/service.

In the case of a ShapeShift transaction, if you've successfully sent funds to ShapeShift but they have not appeared in the target wallet even after a significant wait, try performing a cache reset from Settings. If it is still unaccounted for, contact ShapeShift with the transaction details.