Have just bought a Fiat punto 2001 and the wiring for the radio has been butchered, how can i solve this

If you are installing an aftermaket deck then it will come with a new harness which you can solder into the old one and clean things up. If you have a lacking confidence with electrical wiring then you can take it to a car audio installer and they should be able to repair it for you.

Cheers
Dave