Decompile Precompiled Source Code C #

I had outsourced the development of an Automated Word template Updating tool, that reads properties from an XML and properties from a .MSI and .MST table and adds them into a word document template. Everything works 100% with the tool, but the developer has gone silent on me since I paid for the job and before I could get a backup of the source code - so I need to to have a copy of the source code as I cannot rely on the developer to do any more updates to it and the only access I have is pre-compiled code. To run the tool it uses one simple line of code that os run from a command window. I am looking for a developer who can de-compile the code for me and re-establish the source code, so I have a backup in case we need to update it for whatever reason.