Landline call forwarding

We have an old 171 account that we have been trying for over a month to get one of the numbers forwarded to another number as part of a project, but no one at ATT seems to be able to help.  It is an ATT account, but Verizon last mile.  I have talk to over twenty people, and been transferred, promised action etc all for nothing.  Before you say *72 that does not work, we tried that too!  Cannot open a case online due to the type of account apparently.  We do not have online for this account.  Any ideas?