The "threatening to leave" tactic DOES work, not just with vodafone, but pretty much ANY service provider, whether it's a phone network, or your Sky TV, etc.

I think it depends how you do it, maybe you need to have a viable "plan b" and mention it to them, to prove you're serious, e.g. I phoned Sky once and told them I was leaving because I didn't t watch the TV due to a) too many women in the household watching soaps and b) nothing on at the time I would be able to watch things, so I was essentially only using the broadband service which I could get a lot cheaper elsewhere.

This was obviously a loaded statement and a bit of a lie, but I knew they would counter my threats to leave with an offer of a sky+ box. Lo and behold, they gave me a free box along with a reduced installation, and a much reduced waiting time to get it installed (e.g. 3 days later).

Apparently you can probably get away with the "I'm leaving" story every 12/18 months, and get improved deals.

But onto Vodafone – I had a data plan with them that at the time I thought was reasonable, but due to financial reasons I got rid of the service. Soon after, I started getting text messages from vodafone offering me ever increasingly better deals on a data plan, until eventually I think they were offering unlimited use at the same price I had been paying for just 120mb of usage. If I actually had the money I would have signed up for that

So, I'm due a renewal, and I want a phone that has GPS, and unlimited data plans and a good deal on text messaging. iPhone 3G looks like a good option, but that's on O2. So this is the planned course of action. I'm going to do this while sitting at a computer so I can compare online deals and check reviews at the same time.

1) Phone VF near the end of the month (sales targets might need to be met, meaning deals will be more forthcoming), tell them I am thinking of leaving as I like the look of the iPhone, which they don't have. A similar type of phone would be the Nokia 5800, but there might be others they might suggest. Listen to their first offer, as they will undoubtedly try. I won't force it any lower, I'll just say I'm considering it.

2) Phone O2, tell them I'm thinking of leaving VF, as I like the look of the iPhone, but that VF have offered me a deal to stay. Basically I am hoping they will give me a slightly improved deal than advertised. I don't expect it to be a massive improvement as new customers get good deals anyway, but it's not that important. I will take the name of the person offering it, and tell them I will phone back once I've got my PAC code from VF and my existing contract with VF has expired.

3) Phone up VF again and tell them the offer I've received on the O2, and see what new deal they can offer. Whatever the offer is they can probably do better, so I will take the details down and the name of the person offering it, but will end the call by telling them I'll think about it, but that I will probably let my contract expire and then get the PAC code from them then.

4) Wait for the contract to expire, if they've not phoned back with an improved deal by then, phone them up (again, near the end of the month), request the PAC code, get it, hang up.

5) I've been told there is a period of time in which the PAC code can effectively be cancelled on the new provider, meaning it still stays with Vodafone. Usually within a few days Vodafone will call you, essentially begging you to come back with an improved deal. At this point there's not much more you can do to get a better offer so you might as well take it.

But, if they don't, Plan B is the iPhone which still looks like a decent compromise

Do you think this tactic will work?

And yes, you can get a free N95 with other networks, Vodaphone included. That's the argument here. I'd rather not leave Vodaphone, however after the way they've treated me as a customer, I will be when the contract is over.

Marsha – I'm not a fan of dealers, mainly because they're more likely to go out of business. I signed my Mum up through a dealer and it changed hands twice before she finally tried to update something and ended up going to Vodaphone direct who told her the old dealer had gone bust over a year ago. Sometimes it's just less hassle sticking with the main provider.

Only problem with this approach is that you need to put at least an hour aside to go through the various deals they'll invariably offer and play hardball with them…

Anyway, I've got about 16 months now so I'll see what's around in early 2010 (blimey that sounds a long time away!) and take it from there.