Dial-up connection in WIn 2k server fail

Am not able to make Dial-up Connection to my internet account in Win 2000 Server. i have ISDN line connected to my Win 2000 Server. am using Terminal Adapter OMNI TA 128 . i have configured it on my server. when i dial 172226 my ISP for internet connection. the server adds up Referral Service phone number 0008006501155 & the dial fails . am not able to connect to my internet account suing this line ??

whatz the cause & whatz the solution ??