Refund Request For Amazon Prime Membership Charge

I am writing regarding an Amazon Prime free shipping membership fee that I was charged even though I am not a member and did not knowingly subscribe to this service. Approximately two weeks ago, an amount of $11.29 was taken from my PC credit card for an Amazon Prime fee. After noticing this, I contacted Amazon customer service and explained that I had not requested or authorized a Prime membership. I was informed that the amount would be refunded, but despite this assurance, no refund has been received to date, and the charge is still on my account. I request that this unauthorized Amazon Prime fee of $11.29 be immediately refunded to my PC credit card and that any Prime membership linked to my details be cancelled so that no further charges are made without my consent. I also ask for written confirmation once the refund is processed and the membership is fully cancelled.