1) As Cabin crew what will you tell a customer who has been refused to be served by your colleague? 2) Where would there leave a feedback?

I would explain that since one attendant refused service, then all attendants will refuse service as a matter of policy.

the customer can then direct their complaint to a Gate agent upon debarkation, or directly to the airline via the website's customer service contact information. but basically, they should realize its a lost cause. the cabin crew and flight crew have ultimate authority on board.

1) Unless the customer has asked for the person in charge for that flight, one should not get involved in other colleagues decisions with a customer. If the customer had gotten drunk,I would mention it to my fellow colleagues that the passenger in seat X had his limit but there is no need to confront the passenger about it.

2)Assuming that you are referring to the customer leaving feedback, they can talk to an agent or representative when the leave the plane, or call customer service when they get home/hotel where ever they are.

"Give me $50 and I will slip you the bottle!"