Can anyone tell me which is true and how to go about it?

Peakoverload

Why do mobile phone networks make this so difficult?
Right, long story short. I'm currently with Vodafone who completely screwed up my account at one point losing my number that I've had for years and the only way to resolve it was to get a new number. As a result I'm super nervous about losing my number again. Anyway, my contract is up for renewal but Vodafone still have the best deals but only if you go through Carphone Warehouse as all the deals with Vodafone direct are massively more expensive.
So the thing is Carphone Warehouse have a deal for the phone I'm interested in for a 24 month contract with Vodafone with 18GB of Data and unlimited texts/mins all for £38 a month with £99 up front. However this is for new customers. If I do this as an upgrade, this package isn't available and the nearest to it is more expensive. I spoke to Vodafone asking them if I bought this new phone and contract could I get my existing number moved to the new one and the old contract terminated. Essentially doing a PAC code but not leaving them, just moving to a new account. They said that whilst it's possible it's very complex and there is a risk I'd lose my number!

I asked the same question to Carphone Warehouse and they just said "no you can keep your number". When I asked them how, they didn't go into any detail. Whilst I'm sure that it is technically and legally possible to keep my existing number I have little faith in Vodafone actually being able to do it. Does anyone have experience of doing this, especially with Vodafone, is it possible, did it go to plan?

eDicky

Don't believe Carphone Warehouse, the salesman's only priority is to sell you the contract and they'll tell you anything.

Don't let Vodafone handle it, if there's any possibility to screw up they are very likely to do so.

A PAC is only used to port your number to another provider, not to another account within the same network. You could port to a PAYG SIM on another network, such as Giffgaff or Tesco, then port it again to your new Vodafone account when ready.

Have you considered and priced buying the phone you desire separately SIM-free and taking a SIM-only service that suits your needs? It's likely to be even cheaper overall.

Peakoverload

Yeah I did price up SIM only and it's £4 a month more expensive but £100 upfront cheaper. The annoying thing is that I absolutely hate Vodafone, their coverage is fine, their prices are good but their service is shocking. It's just that nobody seems able to come close to their prices