can't manage features online or through app & customer service isn't helping ...

What service are you talking about? If digital phone service check your outgoing caller ID.

can't check anything, thats what i'm saying & i am talking about managing your home phone features, as well as the absolute lack of help & customer service here, can't check or do anything ... 

Thank you for reaching out to us, we'd be glad to provide clarity on that information, @cosmic_gia.

Check out these solutions for website and browser issues:

• Delete Cache & Cookies - Think of this as housekeeping for the browser. 
• Flush DNS - It may improve how web pages load. 
• Disable IPv6 - It may improve browser load times

You can find more troubleshooting tips here in the Forums.

We also have a few questions we'd like to ask so we may provide you with the most helpful solutions.

• What error messages are you receiving? These details will help us better understand the situation.  
• Have you tried different browsers such as internet, chrome, safari? This error may be due to the type of browser you're using.      

For further assistance, we are always here to help.

Harry, AT&T Community Specialist

So I'm assuming it's digital service? If it's a traditional landline you can't check the features online. No one on this forum has access to your account nor can we fix website issues, you'll have to work with tech support. If you aren't getting any help through the normal AT&T channels file an FCC complaint. 

i know that, but they may be or may have been experiencing the same issue & have some valid ideas or information on how to resolve this, as customer service & tech support is & has been absolutely useless & yes thank you, i had planned to contact better business bureau & i will look into contacting the FCC as well, point is ... the web site & app are not working properly, and customer service has just lied to me several times now.
i have always managed my phone & e-mails through the website but this last month or so nothing has been working, i just get error messages & or a blank white page & they already have screen shots of this & are well aware, but this should not be so complex & hard to fix that I have to be repeatedly lied to & given the run around & some one from customer service should be able to make manual changes from thier end, its just absolutely absurd & ridiculous that its taking this long & wasting so much of my time, as its just totally unprofessional.

Here's another topic on the issue