ChatGPT Plus. How can I use the version that I paid for?

“Dear OpenAI representative, I upgraded and paid $20, but I’m currently using the free version of ChatGPT Plus. How can I use the version that I paid for? I’m waiting for your support regarding this matter. My name is Levent BIYIKLIOĞLU and my email address is leventbiyiklioglu@hotmail.com.”