How to cancel the interesting installment by texting?

You can't cancel it. You'd better return it. If you are 10 days late, you may have three times as much money. If you graduate, you may buy a mobile phone, but you have to pay back the house price. It is because students tend to ignore these things that they benefit. It depends on your late payment and default. After graduation, millions of debts will not come back until later, which may be infinite. They naturally have a way to take the money, but the way may be bad for you, so be careful.