Switch and Save - Debit Card

Recently switched from Verizon to Tmobile. 5 total lines. We are waiting for the validation side of the Keep and Switch program. My question is - will the virtual pre-paid card only be used to pay back Verizon? or can I use it anywhere? so for example - Verizon charges me for the devices, they take the funds out of my account, I use the pre-paid Mastercards anywhere I like. Or do I have to use the prepaid card and contact Verizon to pay?