Make sure you do have a Email&Web function active on your line.
(or have a Email&Web&Voice plan)

Try another page? It might be that the page you are viewing is restriced.

If your on a BES, make sur the company policy does not block you from accessing sites (verify with your IT responsible of the BES)

Resend your Services Books by your BIS acnt (if using BIS naturally)

What has been confirmed to me is that :
all Email&Web functions below 60$ (E&W25, 40) had their WAP browser removed (or in this case, blocked)

But your Internet Browser should be fine

If all that didnt work,
Contact *611 on your phone, explain the problem, you'll be transfered to the DNA departement, then explain the problem again and it should be fixed.

Usually an IP address problem