Overweight carry on baggage fee 60.00

Do not fly jetstar, they charged my partner $60.00 for overweight carry on luggage, they only allow 7 kilos, we were so shocked we didnt check the weigh trolley they used, i find this hard to believe as we were returning to adelaide from cairns and we had all summer clothing in our bags the toiletries were in my bag, yet they said his was overweight, they charge for food, coffee and snacks, fly virgin you get free food, drinks and complimentry checked in baggage . Lesson learnt wont fly jetstar again