Thanks,
Since posting last I have bought a heat mat and temps are much higher now. I keep it on 24hours and closely monitoring the humidity now its warmer in there. They seem really happy with the changes ive made as they have a different type of substrate now like a carpet/astro turf. It's not though, I got it from the pet shop but not sure what its called. Ive got them a new hollow branch too and they love hiding in there.
It's funny how a few simple changes make for happier frogs.