He placed 17 separate online transactions on the Hell's Pizza website using the fraudulent details, the summary said.
Dixon told police he obtained the credit card details from the Telegram app which were dropped by unknown people and he used those details to make online pizza orders.
The summary said Telegram is a freeware, cross-platform, cloud-based messaging software and application service. The service provides "end-to-end encrypted video calling and file sharing".
It said Telegram had "countless forums where credit details can be obtained for free".
Dixon's lawyer, Dafydd Malcolm, said the offending happened after Dixon had been released from prison on other matters and was staying in emergency accommodation.
He said he could have some employment prospects.
Justice Greg Hollister-Jones remanded Dixon on bail to reappear in court for sentencing on April 30 at 10am.