SSRS Dynamic column names

I have a stored procedure (which pivots and unpivots values) that runs as the backend of an SSRS report. The user provides 2 inputs (BeginRange and EndRange).

The results change according to user input and hence I need to reflect those changes on the report as well. The problem is, once I have the report done, as soon as I supply a new input, the report fails because its still bound with the old column headings. Is there anyway to change the column headings and the TextBox values dynamically?

Sample result data is something like:

The column headers will change from week to week. How do I get this ever changing report on my SSRS report?

The problem isn't quite what you think it is:

Yes, you can change the column headings and textbox values dynamically. But this won't help you.

The fields (columns) returned by your data source can not be dynamic for a SQL dataset.

You need to establish a fixed set of fields that your query will return, and then you can pivot those or select from the set of columns dynamically when displaying the report. For example, if I wanted a report to display:

                June   July  Aug   Sept  Oct   Nov   Dec
Department A     20     25    33    36    48    29    35
Department B     22     24    30    23    40    20    33

Then I would design my query to return:

Department     Month    Quantity
Department A    June    20
Department A    July    25
Department A    Aug     33
Department A    Sept    36
Department A    Oct     48
Department A    Nov     29
Department A    Dec     35
Department B    June    22
...

The query results you provided will be difficult to use with SSRS: can you modify the query or create another to return fixed columns, similar to what I indicate above? At the very least, you will need to change the field names (column headers) so that they do not change from month to month: month1 month2 month3 ...