Synchronizing Availability with Vendor File

Recently, a massive problem has arisen when working with synchronization of availability with suppliers via xml. The goods from the supplier are constantly in stock, we get the availability of constantly jumping, that is, it is not. This has a very negative effect on working with the Rozetka marketplace, as it kills the issuance of a product card on the Rozetka. Plus, one more problem, if the goods are running out at the supplier, and we have this product in stock and credited, then it also writes that it is not available, that is, the product lies and is not for sale. How can this issue be resolved promptly, we are losing money because of this problem. And in manual mode, putting down the presence is unrealistic. We look forward to your prompt assistance in resolving this issue.