How to make your online store fully trustable for both customers and producers?

The whole point of an online store is to make profit, from iTunes, to Google Play, Patreon to any other online store. Now if you are an artist, like a musician or electronic painter, and can't or don't want to make your own store for your own products, you would have to put your product on these online stores. Now my question is, how can you trust these stores, I mean in practical manner?

Here is the case(s): You make a piece of music, you put it on store X so they would sell it for a few dollars, or bitcoins, or what ever. They sell it 1000 times, they report back to you that your item has only been sold 15 times, and from that they only give you 70%.

How can this kind of fraud be detected or prevented?

I know a possible solution would probably be to just buy your own item a lot, and see how that will work out. Or possibly give the store a software to sell for you, and make that software to only register with a specific server that you control, and check how many copies are out there. But even then, the store can simply say that someone has stolen the copy, or I don't know someone is distributing their copy, and it is not the store.

Another solution might be a 'good store' allowing you to run a specific code on the web page that appears right after the payment, so you can probably put more trust into the store buy using that code to check with yourself how many times your item has been bought. But again, it is possible that if your item goes somewhat viral, with a lot of purchases, the store might decide to not run the code, every few purchases, to increase their own cut.

Also, this kind of activity is very probably not limited to only online stores, many affiliate programs can and are (sometimes) doing this. As an example I got about 90 people to register through my referral code to a website, and I checked with all of them and 76 had registered with the website on their phone, but even after a month the website reported that you have only referred 25 people, and when I emailed them about the incident (no accusing them or anything just mentioned the problem, and that maybe there was something wrong with their system) they said proudly the system was fine, and there was no problem, and that could have only happened because all the people registered at the same time!(!!!!). Online stores (specially with digital products and assets), referral programs, stores with promotional codes programs, are only a part of the way that stores can be stealing people's money.

Now although I mentioned some methods of preventing this kind of fraud, what are some verifiable practical ways to detect, prevent, and report such frauds in online stores you have to trust with your digital products?

Also, to prevent any more misunderstanding, let's just look at this from a different perspective. Let's say you want to start a new bitcoin store that producers and artists can totally trust, because you give them the ability and enough transparency that you are giving their right cut. How can you implement this in your online store?

Addition: I have already asked this question on superuser, they told me this was offtopic, then I moved it here. Can someone please tell me where is the best place to ask this? or can moderators move this to the appropriate site please?