Unable to sign in after requesting new service

New customer. Just bought a house. The prior owners used xfinity, and the xfinity website says the address is eligible. 
I chose a plan, set a time, and made an account. I verified my phone and email. Now the website won't let me sign in, and I have no confirmation that anyone is coming at the requested time. Everytime I try to open the account, the site crashes. I can't chat with an agent because I can't sign in! Please help!