Shopkeeper on Delhi metro tried to scam me

So today I saw this heart shaped container with chocolates in it and thought it would be a great Christmas gift for my gf. I asked the shopkeeper "how much for it" and he said 180 rupees. I felt hesitant at first but then I thought they must be high class chocolates so I paid him the money. However before giving it to me, he scratched something on the box. When I saw the MRP it had been scratched by someone, definitely by the shopkeeper. There was another container of the same chocolate box there and I asked him "show me that one" and he told me it is expired. When I insisted I wanted to just see the other one to check something, he got really mad and said that he can give me my money back but I shouldn't enquire him too much. Then I left the place after taking the box with me. After going 5 metres away I Google searched with the image of the box and it showed it was actually only 75 RUPEES on amazon. I went straight back to the shopkeeper at Metro station and told him I didn't want it. Then he straight away returned me the money and said "we don't have time for these matters" Please be aware. Never buy anything if u can't see the MRP on it.