Leahjones7
The reps should reply soon. It won't be until at least Monday, as they aren't on during the weekend, but they should reply and may very well ask for the sales call review before doing so.
RBeck
You may still be able to upgrade to the 50GB plan through the Shop/Upgrade tab at the top of the page. Upgrading or downgrading plan levels on the same service shouldn't extend your service contract. Wtih this said, when I just looked it gave me the option to either upgrade to a larger plan at regular price without a contract extension, or upgrading to a larger plan at a discount if agreeing to a 24 month contract extension.
If by "clock" you mean how long you can do things in high speed, it's an amount of high speed data, not an amount of time.