Cannot sign in to account or email

For two days I cannot sign in to my online account or email.  I requested yahoo user name and the one that was sent is one that I changed two years ago.  Now, I cannot pay my bill.  Because of this strange behavior I am afraid to use the not sign in method.   I tried chat, but it went into a loop wanting me to choose a department, but there is none for website sign in.  What are they doing?  Perhaps, they want everyone to be late paying so that they can charge for past due????