We've had a billing issue over the last week that has affected a few people and unfortunately charged them twice. FWIW, you weren't paying $60 for 6 months, you were paying $60 for a year. Regardless, that isn't what you wanted to do, and our support team will be in touch with you later today to sort this out.
I noticed the ticket never made it to the support queue which is very unusual, that's why you haven't heard back yet. But I've placed it on priority. We'll also offer you a year of SitePoint Premium as an apology for the inconvenience.