Luggage charge

To Whom it may concern,

Whilst checking in on a return flight to Melbourne Flight JQ439, 21st of July. I was shocked to find through no fault of my own that my return luggage was not included in my pre-paid flight,
The attendant at the counter was also surprised as it should have been automatic as my baggage on the the way had no problem . I was stunned at the 70 dollar charge as apposed to 20 dollars !!!!!! . Jet-star prices are not cheap anymore with the extra costs . Common sense should prevail as why would I pay for luggage one way and not the other ?.... This explains to me why people take sooooo much hand luggage on board to avoid the cost . In doing so it is very disruptive to the boarding of the aircraft . I would like this matter rectified .

Thank you,

Deanne Marshall.