Why is my SSRS report showing old data?

This might help you The solution I came up with was to render the barcode as a dynamic image on our webserver and reference the image from the report. It works beautifully. I just wanted to post a possible solution for others in the same boat.

This might help you Ok, this is the answer that OP ended using and was his entire idea, I'm just posting it because op doesn't currently have enough reputation to do it himself:
"Ok, Here is the solution: I had to add another column to the tablix and add a textbox within it which holds the Department name. Then I hid the column from the report, and set a reference to that textbox within header. The name of the textbox within the tablix was named DepartmentName so within the header, I added a textbox with the expression =ReportItems!DepartmentName1.Value. Works like a charm!!! "

wish helps you I do not think this kind of graph or functionality exist in SSRS yet but you can look at the third party graph technology like Dundas.
DEMO

I wish this help you I went to report server and looked at the XML of one of the data set which was creating problem and found out that the new FIELD I have added is not there. Then I tried to deploy that data set and it said Overwrite Dataset property is set to False and that's why it was not deploying and I missed it in messages when it deploys a solution. So I simply set the property to True, deployed it and viola problem is solved.

Hope that helps As requested by @CodeswithHammer I'm adding this reference to another thread for just to save people some time searching for it.
https://stackoverflow.com/a/22000827/1807669