Upgrade broadband product, double line rental charge

[#1]

I'm trying to upgrade my broadband product from value to extra online. I'd have thought this would change the monthly cost from £6.49 to £11.49, because I paid for line rental upfront, but the summary screen is saying I'd need to pay for line rental again if I change my broadband product, bringing the monthly cost up to £24.48. This doesn't seem right, as I've already paid for line rental - at that rate I'd be better off sticking with value broadband and paying for extra usage, as I'm unlikely to use more than 25GB. Does anybody know why I have to pay again for line rental?
Thanks,
Amanda

[#2]

Quote

Does anybody know why I have to pay again for line rental?

You don't, AFAIK it's just that the automated upgrade system doesn't seem to be able to cope with Line Rental Saver.
I'm sure one of the Digital Care team will be along shortly to confirm....  
Edit: its explained on this thread http://community.plus.net/forum/index.php/topic,104810.0.html

[#3]

Thank you - hopefully that's worked alright now then. I'll have to wait 'til I'm next billed to find out.

[#4]

Sorry for the late response but MisterW has it right.
Correcting my crazy error

[#5]

Heh, watch who you're calling a hairy biker, Chris