Just contact CS on their site to see how the process goes and the guide because you will find a way to deactivate it, I have experienced cases like that usually there will be requirements that we must meet there are some that they may ask for including information on the last deposit or other, if you have found a way from their CS and you have solved your problem.

Always save the backup code for your 2fa code because it's very important don't put it in one place to store the 2FA backup code, this should be an important lesson for you to save it so it doesn't happen again like this losing access and bothering you too later, especially if there is the large funds you left there might cost you.