Shrink Database Did Not Reclaim Much Space
When using the DBCC SHRINKDATABASE statement, you cannot shrink a whole database to be smaller than its original size. Therefore, if a database was created with a size of 10 MB and grew to 100 MB, the smallest the database could be reduced to is 10 MB, even if all the data in the database has been deleted.

However, you can shrink the individual database files to a smaller size than their initial size by using the DBCC SHRINKFILE statement. You must shrink each file individually, instead of trying to shrink the whole database.