thank you both. it helped me a lot :D @chin.billy.leung YES, we definitely have such supermarkets. I think that everybody has, lol.

The slang 땡깡 refers to '떼' or '억지'. 땡깡부리다 is equivalent to '떼를/억지를 부리다/쓰다 (to badger or pester).

let me give you a scenario first then you go look for an appropriate translation I dont know if in Romania there is equivalent of Mega Walmart stores as in N. America but here they place a lot of candies bars at the entrance of checkout cashiers. They are put in such obvious places that a child would not miss seeing them on the way out with their moms. Occasionally I will see a child cry and cause lots of trouble to their moms because their moms refuse to buy these candies for their kids. The way a child insists and takes full attention of the public by crying is a good situation to use 땡깡 부리다. I would say 땡깡 is used mostly between an adult and a kid in ultra-familiar setting. Between peers I do not think it is appropriate word to use. 우기다 is a more appropriate word to use between grown adults.