Do not cancel direct debits mid contract - there is no benefit in doing this as you rightly state your credit rating would be harmed by this action. Three have insisted to me too that this is the section (4.1(b) ) that prevents me from cancelling my contract under section 10.1(d) However, if it is read correctly, it says no such thing. Section 4, as I read it, allows three to do what ever they please to change your contract - they could raise prices by 1000% should they choose. Section 4.1(b) relates solely to their requirement to notify you about changes and has no effect whatever on section 10.1(d) They kindly point out three cirumstances in which you may cancel the contract under section 10.1(d), but this list can not be taken as exhaustive as if it were intended to be so, the condition would need to specifically state this. The only limiting factor for being able to invoke section 10.1(d) is whether or not the change is of "detriment" (in the case of iPhone customers) or "material detriment" to other customers. If you can prove either of these, then section 10.1(d) applies - RPI is nothing more than a red-herring in this instance and has no relevance to section 10.1(d). Three are attempting to make RPI significant by insisting that because the price increase is at RPI or below it is not a detriment. Three do not have the legal right to determine this - only a court can do so. OFCOM, the regulator has indicated that RPI increases are not of 'material detriment' but this statement was made in relation to a different company and a different contract (a significantly better worded contract by all accounts). Three have clearly made a total pig's ear of this price increase and are now desperately trying to justify the fact they are not willing to abide by their own contract. Getting Three to take their customers seriously is going to be difficult but not, I believe, impossible - 1) Word of mouth is a very powerful marketing tool - one happy customer will perhaps mention it to a couple of friends but a disgruntled customer will mention their bad experience to many, many more. I personally am now almost evangelical about telling anyone who's willing to listen how bad Three have treated me and how they would be crazy to sign a contract with Three. If enough people do this, Three will have difficulty in getting the new custom it so obviously craves. 2) Check your insurance policies for 'Legal Expenses Insurance' You may have insurance in place to pay for Legal action in consumer disputes such as this. If this is the case it might be an idea to investigate using the courts to compell Three to abide by their own contract. The more successfull small claims that are made, the more likely Three will cave in. 3) Write to their parent company in Hong Kong, pointing out how unhappy you are to be treated in such a dishonorable way. This may have no effect what ever, but it will raise awareness that the British public are not happy to be given the run around. 4) Terminate your contract as soon as legally possible. Do not cancel direct debits mid contract - this is not going to help you and will in all likelyhood not harm Three all that much either as they will simply sell the debt to a collection agency. Whether or not Three will notice or even care that a whole bunch of previously happy customers are no longer willing to do business with them is open to question, but it's worth a try.