Bad service and damaged goods

We saw that our polos service light is on so we took it to ntt volgswagen for a service when we got our car back it made a wierd noise. We phoned them to come and fetch the car we didnt want to drove with it like that they came and drove it away. And said no its not on them. But when we gave them the car nothing was wtong and when they gave it back it made a noise now they say we must pay to get it fixed... But nothing was wtong with it it only needed a service...