Free Traffic Legal Advice

Hi All I was wondering if I could get some advice please on quite a crazy situation.

A friend of mine is currently serving a jail sentence and has been for over a year.

• Whilst inside there are multiple people that have been going in an out of his house to feed the fish, collect the post, check on everything and as such his vehicles keys and vehicle where there.
• Someone (we don't know who) has been using the vehicle (assuming it is his car that's been used and not cloned plates which may also be the case)
• As such there is now 2 ULEZ charges and 2 Birmingham Clean Air Zone Charges which have gone through to the courts and they are looking to recover significant amounts (£280 each for ULEZ and £190 each for Clean Air Zone)
• I did attempt to contact both ULEZ and Clean air zone when the fines originally came through to explain that the registered owner and keeper is in prison, I provided a solicitors letter proving the same and both councils came back refusing the challenge saying it is still his responsibility.
• How can this be so if he; 1) Has no knowledge or control over who's used the car as he is sat in a prison cell and 2) has no way of paying the fines or reading the correspondence whist inside? 

Is there anything we can do or anyone we can speak to about it? The correspondence now are talking about TE9 forms but they are for failed procedures if I understand that correctly? and they require you to pay for it to be signed off by someone?

I don't actually understand it all to be honest I just want to try and resolve the matter even if it means me paying out of my pocket the original fine amounts and getting it back off him as and when but paying out £560 to ULEZ and £380 to Clean Air Zone is just too much.

any help or advice would be greatly appreciated.