English Wine Shop — charging extra money from everyone and they don't have price chart outside

Address:

ENGLISH WINE SHOP, UNNAMED ROAD, SORKHA, NOIDA, UTTAR PRADESH- 201304, Gautam Buddh Nagar, Uttar Pradesh, 201304

I went to english wine shop (Unnamed road, sorkha, noida, uttar pradesh-201304.)
Where i asked for imperial blue superior grain whisky half.
First they said give me ₹280. I told them but original price written is ₹270 on the bottle why are you taking ₹10 extra? And why i don’t see any price chart here? They abused me and said we don’t want to see you here again get lost. I think they are charging an extra money from everyone. So i request you to please secretly sting operation here and cancel their license.
Thank you!