Does anyone have a good way to shop for bras from startup companies that doesn't involve sending different sizes back and forth in the mail for months at a time?

I get it, real estate is expensive in big cities. But can I at least get a Bento box with 5 sizes to test out? Or can you hire a person to drive around in a van that has all of the sizes? I will meet them anywhere in my city.

Latest experience prompting this post: Re-ordered the same size I wear in ThirdLove, but it no longer fits. Live chat customer service person suggested ordering ½-cup size up to see which one fits better. It takes another 10 days to receive it in the mail, during which I receive a bunch of obnoxious email reminders about how I'm taking so long to send back their bras (even though they are responsible for the delay through their slow delivery systems). The second version didn't fit right either, and they are telling me that they can only do one exchange per order, so I just need to buy an infinite number of their bras. It could end up taking me 1-2 months just to buy a replacement bra.

Prior irritating experience: Tried to purchase panties. Since I didn't like the fit, I just had to keep them and THROW THEM AWAY. This is all because they don't have any in-person fitting rooms. This is actually bad for the environment in addition to not solving my problem that I wanted to buy underwear.

Any recommendation for a bra startup that has the quality/feel of ThirdLove bras, but where you can actually try things on before buying?

p.s. It's extra irritating when the customer service people can't solve your problem but they are using adspeak to talk to you (e.g., "It's time to trade-in for a bigger cup and give your breasts some breathing room!"). Maybe... maybe... but only if the bra actually fits and I don't have to pay triple for it!!