ChatGPT Plus subscription renews on a different account

I had the ChatGPT app downloaded on my phone and used one of my other accounts to access it. I stopped using that account, so I decided to start a subscription through my iPhone for ChatGPT Plus using a different account of mine. I logged into ChatGPT on my phone with my new account and then went to subscribe to the Plus plan. However, the phone automatically activated the subscription under my old account instead of the one I intended to use.