I used renotech very recently for a lot of work on my car, I even drove across from Manchester.
Work I had done was new exhaust manifold fitted, new exhaust system fitted and Cambelt service.
Price was exceptionally fair and service was really good.
Please be aware though that they do not use OEM parts for the Cambelt.
They use OEM spec parts (made my the same manufacture of the OEM parts but without the Renault stamp, hence the cost decrease), and they also provide lifetime warranty on the Cambelt itself (6 years or whatever mileage it's supposed to be) in case it snaps.