Go ahead and cancel your order if that's your impression.
But I thought they had contacted their first batch customers apologising for a brief delay and advising they would include a spare battery as a gesture (of goodwill) for their understanding.
I've been in business a little longer than you, 43 years to be exact and like most businesses, rely on suppliers for products and components. When launching new products, you endeavour to make deadlines and release dates. Mostly these things need plenty of advance planning. Having a key supplier late for whatever reason is not entirely unusual especially by a few days. I strongly doubt iBasso did anything deliberately as they are a very small company. I'm also aware that in China there has been a severe heat wave affecting some manufacturing plants getting sufficient power from the state owned plants in some regions. This could easily be the reason for delays in supplies. Just saying. Have no idea if this affected iBasso but it has some of mine.
You are entirely entitled to your opinion. I just think you are either being harsh or you really don't want your DX50 and justifying your cancellation. I'm sure someone else will gladly accept yours.