<human>: Provide a brief overview of the text.

My contract with Vodafone Australia is nearly up, and I tried to upgrade my phone to a Samsung Galaxy S4. I called the necessary phone number to do the upgrade, and started speaking to a guy about what plans I could get it on.

I asked if I could remain on my current plan (The new ones are quite expensive) and the VF sales rep said that I could, and amazingly, the phone was turning up as $0 per month extra!
I happily accepted this offer, and the rep went through all the terms and conditions. I agreed to everything he said, and thanked him for the awesome deal.
The conversation ended and we both went on our happy ways.

About 45 minutes later however, the same rep called me back and said there was a mistake. I could not get the phone on my old plan for $0, it would be $35 p/m instead.

He also added that there was an extra charge of $270 left on my account (even though I was in my free upgrade period). There was a whole bunch of transfers between departments, and a lot of "only that other department can answer that question."

What I really want to know though, is whether the first agreement that we came to was (even though it might have been an error) legal and binding. 

The final person I spoke to said they would get back to me with a final answer within a maximum of 48 hours, this was 72 hours ago.
<bot>: Vodafone gave me an upgrade over the phone with a great deal, then they called me back to stop that deal