Hi,
After reading some of the horror stories you see on here I thought I'd share some tips and advice.
1. Normally verbal contracts are not binding. However, as these call centres record ALL sales calls, and your consent can be noted, then contracts agreed over the phone are legally binding and enforceable. Be aware of this before agreeing to anything.
2. Under the Distance Selling Regulations, when you agree a contract over the phone, you have between 14 and 28 days to cancel your contract, and you don't have to give a reason. Anything else the seller tells you in this respect is untrue.
3. When you recieve a phone call from a sales team purporting to be from your provider. Remember to ask them explicitly if they are phoning from your provider. Quite often 3rd party sellers user cleverly worded scripts to make it sound like they are representing your provider when in fact they have nothing to do with them.
In fact, some service providers don't even operate outbound call centres. For example, I received a phone call one day from an agent claiming to be from my service provider and offering to upgrade me. I asked them why they were phoning, because my brother worked for them, and I knew for a fact that they did not have an outbound call centre. They changed their tune and said they were representing my service provider. When I then stated that I also knew that my service provider didn't have any contracts with 3rd phone sales, they hung up. ;o)
If you end up a victim of this it can cause you no end of hassle and money.
4. If possible, always phone the service provider (i.e. Orange, Vodafone, TMobile, O2, 3) in order to set up a contract. Quite often they can offer you deals just as good if not better than the 3rd parties. Additionally, it means you have one point of contact should you wish to make a complaint. You'll have seen from many posts that the cashback offers 3rd parties sell are incredibly hard to claim on or receive any money.