website is only a blank page

I am trying to pay my AT&T bill, but I cannot access the website. I have tried six times over the past two days, using a PC running Vista and a laptop running Windows 10. I got onto att.yahoo.com and tried getting to att.com through old emails, but I can only access "business"-related links...nothing "personal". When I go to att.com, I get only a blank page that has some silver shading up in the corner.