Both the Sender and the Receiver should receive SMS confirmations after completing a Send Money transaction. However, due to signal intermittency, the SMS may have not pushed through.
Even if there is no SMS confirmation, the money has been sent to the Receiver and has been added to their wallet balance.
To confirm this, you can check your Transaction History on the App. Please take note that this entry will only be reflected after 24 hours.
To view your transaction history, log in to your GCash account then tap on Activity on the navigation bar.
Refer to this article if you have accidentally sent money to a wrong number.