Dodgy Sunroof

[hugoboss]

I have a VW Golf. The car has a 'can opener' sunroof job on it. Today i realised that rain has come through the sunroof because the seal has come away. It is only for about 3 inches, but enough to let water in during heavy rain. I have no idea who fitted the sun roof and VW won't touch it. Anyone got any ideas on how to solve the problem? Much appreciated. Thanks