I agree with Factor30 in the first instance - contact the regulator. They won't be long in getting things moving in the right direction. But if not?
Give the creditor a full written explanation in the first instance - just as you have done here - that you acknowledge you owe a bill for power used at #22. I assume that your bill for #6 is up-to-date. It will do no harm to CC in your energy provider (the original creditor). Thus giving the creditor the opportunity to correct the mistakes made by both them and the energy provider so that you are being billed for the correct amount for the correct address. Make sure you send the correspondence with proof of postage. Also inform them that unless their errors are corrected you will not pay and will defend any subsequent Court action that may be taken against you.
The ball is then firmly in their court - pardon the pun.
If they continue to pursue payment for money that isn't owed (the £60 addition) and for energy attributed to an address you have never resided at, then fine. You will eventually end up in Court. They will claim you owe a debt for energy used at #8. You will then explain that you never lived there. The onus then switches to them (on the balance of probability) to prove that you did live there. They will be unable to do this and therefore you will then claim that there is no case to answer. You win, and better still, you pay nothing.
If they then come back with a demand for the correct amount for the correct address then ok, pay it.
Alternatively, you could protect your credit rating by paying what is owed and then raise an action against the creditor for 'unjustified enrichment' - or whatever the equivalent is in England/Wales (Beneficial Trust??). Might be less hassle than going to Court for owing debt and then having to get your credit rating corrected after winning your case.