I'm having trouble using the account.

I have paid for the account: fo501.infusionsoft.com
Money deducted in my card account.
However infusion sent to my email is another account. Specifically: fp506.infusionsoft.com
Right now: fo501.infusionsoft.com is not authentically authenticated. This led to my campaigns being stopped.
I would like to consider for some reason that there is a mistake here. I still want to use the account: fo501.infusionsoft.com.
This account fp506.infusionsoft.com is not mine

Hi Nhan,

This sounds like a weird issue! You will need to raise this directly with Infusionsoft support through the in-app chat window. Hopefully they will be able to sort it out.

Whilst you are doing that it might be worth checking the links in emails you received whilst setting up fo501 to see if any of them can get you in. They may still be live! But I would definitely start by raising it with Infusionsoft support.