OK, thanks - I am unclear if you have already made a complaint to EDF?
If not, you can make a formal complaint first of all to EDF here:
If that does not resolve the matter ask them for a "deadlock letter", which is a letter giving their final response.
Once you have the deadlock letter the next step would be to escalate this to Ofgem (their regulator) - they will investigate and liaise with the energy company which would hopefully result in a cancellation of the new tariff. They can order the energy company to make a financial award for inconvenience if they have acted badly.
The service is covered by the Consumer Rights Act 2015 so you have a right to expect a reasonable service which is carried out with care and skill - if you do not then the regulator will step in but it also means you can sue for any damages or losses incurred as a result of the energy company's conduct.
You can make the complaint to the Ombudsman here : http://www.ombudsman-services.org
There isn't another remedy here unless you have incurred a financial loss in which case you can pursue them in small claim via the http://www.moneyclaim.gov.uk site (which is easy to use - no lawyer is required).
I hope this helps - if you can please accept the answer and give me a 5 star rating (there should be a button at the top of your screen to do this), I can answer follow up Q&A's at no extra charge and Just Answer will credit me for helping you today.