Are iPhone with serial number starting with "F" refurbished?

Hello. I bought an iphone 15 pro in Dubai in June this year. At home, I discovered that the serial number of the smartphone begins with the letter “F”. They write on the Internet that this means the phone is refurbished, which upset me very-very much, because the seller said when purchasing that the phone was completely new and not refurbished. I returned to the store on the same day and asked if they could explain to me about the meaning of the letter “F”, they told me that it was just a letter, and the phone was not refurbished, but completely new. They refused to exchange me for another phone. Please tell me, is my phone new or refurbished? If necessary, I will provide additional information upon your request.

Best regards, Sergei

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