Can't change product online

[#1]

I'm trying to change my product from the old Broadband Plus to Extra, which we can get on our exchange for £11.49 per month.
So cheaper and a lot more usage
I've tried to do this on-line, with no home phone and accepted the free wireless router as we're happy with having a 12 month contract. I have added card details to my account so the £4.99 P&P for the router can be taken.
However, I got this message during the last stage of the upgrade:

Quote

Looks like there's a temporary problem here. We weren't able to complete your upgrade. If you'd like some help, give us a call on 0845 140 0200.

I wonder if someone could take a look at this, or will I need to call the above number?

[#2]

it depends on who your phone is with, the 0845 number is free if you are on home phone, but might get you South Africa, the alternative is 0114 296 5198.
But a bright spark should know that
dont think this should affect it http://usertools.plus.net/status/archive/1279890368.htm

[#3]

I don't know it all, this would have only have been the 2nd time I've had to call support in 8 years
It's not urgent, and my billing date isn't until the 4th anyway. I was hoping someone could look or maybe I'll raise a ticket.
I won't be able to call until Monday now, and would rather not have to use the work phone tomorrow.

[#4]

Your card details are out of date, so the account change tool can't charge your £4.99 and throws an error. Please update your details here then it should go through the account change without any issues at all.

[#5]

OK - thanks Ben.
Looks like it didn't save the new details for some reason, I'll try adding the card details again and see how I go.

[#6]

That's sorted it, has gone through now.
Strange as I'm sure when I was trying to do it last time the card I entered was listed.
Maybe it's just me
Thanks for your help.