Refundable flight issue

Hi everyone, I have recently booked refundable tickets to Singapore via Aunt Betty (ik, rookie move, won't be booking with a third party again). However, I wanted to go to Singapore earlier and have booked an alternative flight, and was looking to cancel my flight there with Aunt Betty but they want to charge me $250?!!!! And their terms and conditions say that the cancellation fee could go up to 100% of the booking?!!! This is insane. So my question is, if I do a no-show for this flight, will I still be charged? And the other more important question - my return flight is with this company (which I am happy to keep), but will doing a no show affect this flight/will they cancel it? Any help would be greatly appreciated!