This article is similar to when repricing isn't working and you keep selling something on eBay and losing money. For that article click here.
Automatic Ordering Disabled
First you need to check if you have Automatic Ordering enabled on your account. If you don't, sometimes the following scenario will happen...
1. You are away from your computer or you are asleep or something like that.
2. You make a sale but you have AO disabled.
3. That item only has a few or maybe only 1 left in stock on the source market.
4. Someone else sells the same item but they enabled AO, so their account fulfills the order before you do.
5. You make it to your computer and check your orders only to find out that your source item is no longer in stock.
You should also go to your listing details page for that specific listing in Easync. If you have a number entered into your "in stock quantity override" then that will cause it to always be in stock with that quantity that you have specified. The screenshot below shows an example.
You'll need to remove the quantity and leave it blank and then click save.
Reached Seller Limits
You also might have reached your seller limits set by eBay. Repricing and quantity adjustments won't work if you are very close to maxing out your seller limits. You need to always keep at least 10% of your limits free for Easync to allow items to go in and out of stock properly and be able to handle the dollar amount for the usage on the limits.
You'll need to check on both parts of your limits, your quantity limits and your dollar amount limits.
Click here to read about eBay seller limits and how to find out what your limits are.
Other times bugs from time to time can cause this to happen.
Workaround - Please open a ticket about it AFTER you change the quantity to 0 in Easync, don't do it manually in eBay because Easync will adjust it back again and you might sell it again.
They'll probably keep buying it because everyone else has it OOS but you appear to have it still; you'll be the only seller selling this item so all the people looking for it will come to you and try to purchase it. So make it 0 through your Easync override settings.
Now what to do for your buyer... you can look on other marketplaces for the item, maybe Walmart has it, or Overstock, Costco, Best Buy, Sears, or just google the product and see if you can find it at all. Usually, another market will have it for the same price that your original source market had it.
How to make 0 quantity override
You can do this by copying the Item ID for that listing, then go to your listings page on Easync and paste the Item ID in the search bar and hit enter. Then click the 'details' button on the far right. Then change the quantity to 0 and save your settings. Now go to the actual eBay listing and revise it in eBay and make the quantity 0. Now Easync will make sure it stays at 0.
Now come open a ticket about it please so we can get this fixed.