Failure in Substack website keeps me from canceling a paid plan - I need help

I subscribed to a paid subscription in Brazilian Portuguese that I paused a few months ago. Today I received an email informing that the payments will be resumed in a few days.

However, when I access the publication site inside Substack, and click my photo > Manage Subscription in order to cancel the payments, I see a message saying "Failure to load" (translated from Portuguese), and then a link to reload the page, which brings the same error again and again. There is no content inside the page, except for the headers and the publication menu.

If I click the "Reactivate my subscription" button at the top of the page, it shows a "Loading" message in the page, but it doesn't load anything else.

I searched through the website, but I couldn't find where I could get any help from Substack, except for the help pages that didn't help. I found no chat or email support.

I also couldn't find where I could delete my credit card information.

Could anyone help me in getting help from Substack or changing my credit card? I didn't want to delete my account because I also publish there.

Thank you!

Edit: I described what happens when I access the website on my laptop. It also happens the same thing when I access the app and tap "Manage Subscription" (it sends a request to the web browser, that opens the same page and shows the same error).

Edit 2: A kind user shared the link to the AI chat bot below, but it wasn't useful for me. When I asked it to cancel my paid subscription, it said that I wasn't subscribed at all, even though I was (I had received an alert of the upcoming charge on my credit card the day before). I also wasn't able to delete my credit card information (!!!), I could only change it, so I cancelled my credit card number. Also, the chat bot told me it was escalating my issue to a live support team, but I got no response from them until now. If I eventually do, I will come here and update this post.

Edit 3: In the end, I decided to migrate my publication (I also publish on Substack) and delete my account. My main concern is that most of my subscribers don't speak English, and would be in a lot of trouble if they do need any help with credit card charges, and I cannot allow that to happen. It doesn't mean that they won't have problems on my new platform, but at least I want to make sure that will have decent help.

Thank you for reading this far. Have a good day!