try this c#, plz convert to VB.net, I did some conversion hints try:
dtDeleteSh = dtDeleteSh.AsEnumerable().Where(a => a["DEPT"].ToString()!=prodName ).CopyToDataTable();
Sample vb:(dont know it's correct syntax)
dtDeleteSh = (From del In dtDeleteSh _
Where del!DEPT.ToString <> prodName _
the logic is select rows that are to keep and avoid the one's to delete and reassign this to existing datatable.