i would not think so.
Only an adult can enter into an enforceable contract. In Venezuela that is the age of 18.
They can sign it, but it is not legally enforceable.
No, a 17 year old cannot sign an enforceable contract. You must be 18 to do that. However, if the 17 year old confirms the contract after turning 18, (by making a payment or other action) it can be enforced.
Typically 18 years old...however....A minor child (under18) can be in title if the property is held in a "trust" for the benefit of the child. A minor can not legally sign a contract and it be an "enforceable" contract.
molting
A nine year old cannot sign an enforceable contract. The parents do not have to honor it.
"Spoils System"
It depends on whether both sides gave new consideration (something in exchange for something). If only one party did something different under the contract, then it is gratuitous and only the original contract is legitimate. If both parties offered something new to the contract then there is a new contract formed and the old contract is thrown out.
Usually by removing the old switch and replacing with a new switch.
Sorry. No. You're learning a hard fact of life. Verbal "contracts" are not legally enforceable. The old saying is very true; "A verbal contract is worth the paper it is printed on."
No you can just get everything transferred to your new phone.