Consuming a Codeunit Web Service problem

zac

Hi guys,
I have a problem with consuming web service codeunit on a couple of different databases.
I’ve used the walkthrough example from Microsoft link.

I created the codeunit for receiving price/rebate on three different databases (for different customers). Codeunit is the same for all three databases and when I call them via C# web service I only change URL.
Problem occurs if the different users send the request for the same article in the same time and then they as a result get back wrong price/rebate.
For example. user x request for article no. 0001 but in the same time user y send request for article no. 0001 but on different database (different price/rabate). As a result in C# web service I get switched values.

Does someone has an idea how solve this kind of problem?