Upgrading from Dial up to Broadband - Why the delay?

[#1]

I recently moved house and finally had the phone connected yesterday. I wished to use an old dial-up account I've kept active (although not used for a while as at my previous address I was using another family members broadband service) and upgrade it to a Plusnet Extra Broadband package.
Given that my phone line wasn't connected until yesterday I didn't have confirmation of the phone number so couldn't sign up until yesterday. As it turns out my dial-up account was billed 1-2 days before the phone connection, so when I completed the account upgrade forms online (well I say completed they kept erroring on the last step), I was informed that I'd have to wait until the 24th of September to get Broadband.
I have raised this issue in support tickets (and the error that was received), but have just had the same answer back that the month delay due to billing periods is "the way the system works".
Personally I don't care if I've already put out £5 this month for the dialup, I just want the Broadband service asap. I also find it hard to believe that there's no way you can expedite the upgrade on the account.
I have also been informed that the request has gone through despite the error messages, however I have received no actual confirmation of this, nor is there any indication when checking my account online that it has.

[#2]

Why not refer yourself and sign up on a fresh account?  Might move a bit quicker but don't know about the referral money - perhaps it is not allowed?

[#3]

The only reason was I wanted to keep the account, as I've had it since 1999 and still occasionally get e-mails (albeit not that many) to the associated addresses. To be honest if it doesn't get sorted in the next couple of days, I will probably just sign up for a new account, either here or elsewhere.

[#4]

Hi alphasigma,
Just letting you know that I'm looking at your account now to see what's going on and see if I can intervene. I'll reply back ASAP

[#5]

I've just replied to the ticket you sent back. I'm sorry to say that you were misadvised, this will be fed back to the agent in question who replied to you.
I've actioned an upgrade which means we create a temporary ADSL account which will be activated and changed to Extra once your order has completed.

[#6]

Thanks very much, Adam.

[#7]

I checked the order status this morning which stated that there was a problem at the "Checking Your Details" stage:

Quote

We've found a problem with your account. Please note the following details: An internal error has occurred that we are currently trying to fix Please contact us for more details and we will be able to sort it out and progress your order.

I queried this on the ticket that had previously been raised and have just received the following response:

Quote

Thank you for getting back to us. I have checked the status of the upgrade and this is due to happen on your next billing date

I'll admit I'm at a loss for words, not only does this not answer my question about the problem on the order tracker (which is still showing up), but is again stating that the upgrade will not take place until the 23rd of September, opposed to the 7 days you quoted yesterday.

[#8]

Sorry about the delay in getting back to you, I've done an instant account change, applied 100% discount to your next bill and fixed your fault, you'll be back online tomorrow.
I'm sorry that it took this long