Who to contact?

[SnowyMouse]

I want to complain about the local LTNs, I've emailed my councillor but no response, who else can I raise this with?

What's an LTN?

I don't know what an LTN is either.

Your local council will have actioned this so are the correct point of contact.
Have you searched for the relevant Transport/Traffic cabinet member?
We recently had the majority of our LTN's removed after much persistence from the local population and my gosh it's bliss not to have to sit in a gridlocked car park anymore.
Keep pushing OP-these things are horrendously divisive and do nothing to remove pollution anyway.

Me neither.

It's a low traffic neighbourhood, they've blocked up all the side roads between two radial roads, it used to take me 10 minutes to get to my GP (on the other radial road), now it's taken an hour, and taxis don't want to do it. Also my carers are struggling to get to all their clients.

That's not quite true.
OP contact your local council

www.theguardian.com/environment/2020/nov/16/mythbusters-eight-common-objections-to-ltns-and-why-they-are-wrong