How to get a new phone without credit?

The same way you buy food or most other things that are not free. By paying for it in full when you get it.

You select a "prepaid" phone that costs an amount of money that you have, you pay that amount of money, and you get the phone.

You do not "pay off" the phone.

at 17 you can't sign a contract, you need to be 18

If you have enough money in the bank to cover the payoff of the old phone you can most certainly use a debit card to make that payment

However you will not get a new phone with it and no credit.Your only option is to get a prepaid phone, you do not need credit for that and you buy your minutes as you need them, which can be purchased with a debit card

They have some nice prepaid phones (T-Mobile-AT&T to name a few) and nobody would know it is a prepaid phone but you. They even have smart phones that you can prepay. If you don't tell anybody it is a prepay (and there is nothing wrong with a prepay phone-unless you are on some sort of status ego trip) nobody would even know and I am betting you have friends that have prepaid phones that you don't know about because they want you to think they have these great calling plan, they do it is called prepaid minutes and they all work the same, use the same networks as regular plan phones do

I do not think that any company will allow this. You will have to pay for the phone up-front.