Is the "page from the bank" the 3D Secure validation page - e.g. Verified by VISA or the equivalent for other cards?
http://en.wikipedia.org/wiki/3-D_Secure
If your card needs to be registered with this for online payments or you have locked yourself out of this page then you need to talk to your bank.
If you have some other problem then you might want to log a support query to get 48 to investigate/advise:
http://help.48months.ie/requests/new
Until you can sort out the card payment issue you could top up by voucher instead:
http://community.48months.ie/t5/Most-Popular-Questions/How-do-I-top-up-Overview-of-the-top-up-paymen...
Hope this helps.
