I NEED TO FORFEIT TICKETS FOR DATE CHANGES

I can not believe the lack of customer service I experienced by Skywise. I tried to make use of their lower air fare rates (they are so eager to advertise and promote). Due to unforeseen circumstances my plans changed and I had to change my flight details as well. Phoning their contact centre the agent let me know that she can not change my ticket in the lower class fare but can only change it when I upgrade. Not understanding why I would need to upgrade to change my flight date, she let me know the only option is to FORFEIT THE TICKETS I ALREADY PAID FOR AND BUY NEW ONES?!! Really Skywise are you serious??? I was prepared to pay in for the difference in the ticket changes, but buy new ones, and then lose my old ones.... bad customer experience.