Refunds on a boost
A boost is a publishing fee like any other, so it is non-refundable by default. If a boost charge is refunded or charged back, the promotion that charge paid for stops there and then, and the days it already ran are not credited or given back in time.
What happens to the promotion
Each boost you buy is recorded as its own grant, with its own start, its own end, and the price you paid at the time. When a charge is reversed, Jinu marks that grant refunded and takes its remaining days out of the schedule immediately.
If you had other boosts still running on the same listing, they are not lost. Their remaining time is rescheduled to run from now, one after another in the order you bought them, and the listing stays promoted until that time runs out. If nothing else is left, the Promoted label comes off straight away.
A worked example
You buy Spotlight on the website, which is $5 for 7 days ($5.99 in the apps). On day 3 the charge is refunded. The four days left on it disappear at once and the listing stops being promoted. You are not credited for the three days it ran, because it ran: the listing sat first in browse and in Featured near you for those three days, which is the whole of what a boost is.
The prices, so you can check what you were charged
On the website, Bump is $1 for 1 day, Boost is $3 for 3 days, and Spotlight is $5 for 7 days. In the iPhone and Android apps the same three are $1.29, $3.99 and $5.99, because the app store's commission comes out of what you pay. On the website you can also enter a custom amount between $6 and $50, which buys days at the Spotlight rate. The iPhone and Android apps sell the three fixed tiers only, so a custom amount on your statement came from the website.
Paying again while a boost is running adds time rather than replacing it: the new days start from the end of what is already booked.
Boosts bought in the app
A boost bought through the App Store or Google Play is refunded by Apple or Google, not by Jinu. When the store tells us a purchase was refunded, the same clawback runs and the promotion is removed. Google also refunds and revokes any purchase that is not acknowledged within three days, so a boost that never activated can disappear on its own.
If you think a boost never ran
Check Billing for the charge and the listing for a Promoted label and the days remaining. A boost only applies to a listing that is live, so a listing that was paused, expired or held for review may have taken your money without showing anything. Write to legal@jinu.app with the date, the amount and the listing link.