What Can I Get From Vodafone UK?

My contract from Vodafone end within the next two weeks. I'm after a new phone and I really don't know what I can squeeze out of them.

I've been told that if I speak to my Vodafone shop and am not satisfied with the offer I should ask for my PAC code and wait until another salesperson contacts me. I've been told that these guys are from Vodafones Retention Department and that they have the ability to offer very good deals. So what can I hope to squeeze out of them.

I've just finished a two year contract. My bill was in the region of £25 plus per month.

Let's say I was looking the iPhone 5 32GB, unlimited calls, unlimited texts and 4 GB. Vodafone's website advertise it at £52 month with the handset costing £19. With a bit of haggling with Retentions what could I get that for £25 - £30 month with a free handset. Or is that been to optimistic?

Or say I was to go for the Samsung Galaxy S4 again the site advertises it at 24 months, Unltd minutes, Unltd texts, 1 GB mobile internet data for £37 month again would I be asking to much if I were to look it at say £20 month.

I've heard somewhere that with all the bits and pieces that Samsung has added to the Galaxy that the standard 16GB that comes with the phone may prove insufficient.Am I correct and what should I look for if I were to be offered one at £20 month. Would I be pushing the boat out to far if I were to ask for 2GB data.

I know these may seem ridiculous prices but from what I'm reading Vodafone retention have a very big scope when dealing with retentions. Then again maybe I'm been like Vodafone to greedy. I'm also just trying to get an idea of what it is realistic to ask for.

Work on an effective discount (over 2 years) of 100-150 pounds
MORE if you make a lot of calls that are outside your contract
eg if you travel abroad and cause roaming charges…
either for holiday or business…

Then they like you.
and the extra profit you make for them - so pay some back.

but 100-150 is typical discount
and often you can get it anyway via
Quidco see below (but may have to wait for the right time/offer)
https://www.quidco.com/user/1983737/659661/Vodafone - to Vodafone (free to sign up)

eg SIM free 20.50 (UNL/UNL/1GB) was on offer with 120 back = 12.00/month
so add in iPhone at say 480 pounds = 20 pounds/month extra = 30-32 pounds

but lots of deals as mobiles.co.uk etc (owned by voda)
or carphonewarehouse etc.

You can check again on say billmonitor (put in 2000 mins for UNL deals)
http://www.billmonitor.com/calculator?alt=false

Best deals are often by showing that you have found a better deal
and want to leave for it - let them match it - sometimes they can, sometimes they can't
so be prepared to leave /start a contract (even with vodafone!) via these other sales people.