When I get a phone call and have to enter numbers for automated service, then when I mistype a number, I am not able to back space or see a delete icon. But if I were to make a call, I have a delete button. Very weird
Typing a phone number in your dialpad and typing a number in an ongoing-call/automated service is quite different. When you talk about automated service, it means that the 'automated service' is being hosted on some other computer that takes your input as final and processes it. You can't alter the input in any way. Unlike this, when you are dialling a number in your dial pad, the call is yet to be 'hosted' on a network so you are free to do whatever you want to.