Website support:
No webpage to cancel account.
No information about how to find Three number.
You can't access any customer support without Three number.
Once I found my Three number, I've entered it on the webpage login, but it takes me back to the same page.
I've tried to access using email and password. It said password is incorrect. I've asked to set a new one, but I've never received the email to do so.
Phone support:
Did not recognise my own number, the message kept repeating and I couldn't speak to an operator.
Once I found my Three number, I waited 10 minutes to speak to an operator. He hang up when I said I didn't have access to emails in that moment, despite providing other verification proofs.
The second time I called I managed to cancel my account.