When the argument got heated, the passenger's sister came to her aid, and swore at the flight attendant. Later, another relative got up from his seat, swore at the flight attendant and threatened to hit him.
"You're my employee, I paid for a flight ticket and you'll sell me the chocolate," the passenger told the flight attendant, who was busy with another passenger, while other passengers around her tried to calm her down.
Seconds later she was joined by a woman who identified as her sister, who hurled abuse at the flight attendant: "You piece of trash! Don't look at me!" The sister later repeated the same insults and added, "I'll steal the chocolate from you!"
At this point, another passenger joined the argument, likely another relative, who got up from his seat suddenly, saying: "I don't give a f*** about you, you a**hole!" and adding further abuse.
When the plane landed in Varna, the flight crew contacted the police to report the attack, but no measures were taken against the passengers.
A video documenting the argument was posted on Facebook on Saturday night after first circulating in different forums of Israeli flight attendants.
The Israeli flight attendants expressed outrage and shock at the incident, and asked to add that the violence seen in the video is not uncommon and that they encounter such attacks on quite a few flights.
"It took me a few minutes to take in what I saw in this video and I'm still in shock things like that actually happen. So to anyone who asked 'what's so difficult about being a flight attendant', there you go," one flight attendant wrote.
After the video was posted on Facebook, several of the flight attendants who uploaded or shared the video received threats from members of the family featured in the video, saying if the video is not removed they will turn to the police to complain about the flight attendants.
Ynet received messages sent by the passenger who started the argument in which she writes to the person who uploaded the video: "You ruined my life."
The flight attendant in the video declined to respond.
Israir said in response: "The phenomenon of passenger violence against the flight crew is only increasing. It's even stated in a report by the International Civil Aviation Organization (ICAO). Our job is to do whatever possible to put a stop to this phenomenon primarily for the safety of the passengers and equipment. The video uploaded to the web was filmed by one of the passengers who shared with all of us the type of experience that needs to be cut off at the root. Israir is doing and will continue doing anything to ensure a high and strict level of safety and security."
CORRECTION: An earlier version of this story mistakenly reported the flight in question was to Verona, Italy.