I really don't see that you have a leg to stand on here. It sounds like you will still be arriving at your final destination at the original scheduled time. A slightly later departure from your point of origin isn't really going to make any difference. In fact they could say it's better for you in case of any delay to your (fictitious?) inbound connecting flight!
If you simply want to cancel, why not just check to see what the cancellation charges are and swallow them? On many QR tickets the cancellation fees can be fairly reasonable (in my experience at least). Or see if you can change the flights to another date if that would suit.
I completely agree I don't believe I have a leg to stand on, but I was seeing whether the policies on schedule changes might give me the answer I want, but do not deserve.
In any case my tickets are in I class (i.e. dirt cheap business), they say non-refundable, but I can't fine the exact booking rules at all, a $300 cancellation fee or something I would happily take.
The inbound flight however is not fictitious
