If you are unable to cancel payment on Cash app, then you should know one thing clearly. You can see that, there is not an option to cancel the payment. Even, you can say that transaction complete within a second and it doesn’t show you any cancel option here. But if you still want to cancel payment to get refund from Cash app, so check your activity feed. https://www.monktech.us/cash-app-customer-service-phone-number.html