A company offers a new phone plan where the monthly cost is determined by the function \( C(n) = 30 + 0.1n \), where \( n \) is the number of minutes used in a month. If a customer uses 500 minutes in the first month and 750 minutes in the second month, calculate the total cost for the two months. Additionally, if the customer receives a discount of 15% on the total cost, what is the final amount the customer needs to pay? Let's think step by step and output the final answer within \boxed{}.
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