Help Please :/ S3 Noise

Hi everyone!

I have recently noticed a strange noise coming under the hood from my S3.
It's coming from the left up corner of the engine bay and it makes this rubbing noise.
The rubbing goes like this: ssk circle ssk circle ssk circle ssk circle ssk,.... and when you put your foot down
on the pedal this rubbing goes faster.
This only happens on cold start up and within 3-5 minutes the rubbing is gone!
The S3 was serviced two days ago and Audi said that they havent found nothing to be worry about
and that answer just make me mad as hell!

Any help be apreciate it,i'm really worried :/

Thanks!

Anybody? :/