Someone under the age of 18 cannot be bound by a contract. Cancel the contract and ignore the protests. Make it clear you are cancelling it by sending that information by regular mail and return receipt requested (that's right 2 letters saying the same thing.) Hold onto the receipt in a safe place for when they start claiming you have to pay them beyond the day you cancelled. The only one on the hook is there employee.
This was a really dumb plan. Especially the sales associate using his credit card...
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As a minor, you can "disaffirm" (cancel) a contract, but you'll have to give the "item" that you bought back.
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