Those version numbers are all SP2 - Microsoft just likes to confuse everyone. The number you get back depends on whatever tool you are using but it's just SP2 (10.50 and 10.52)
You can check this thread for more information - it has a link to the connect item where MS reports "It's by design". That just means they aren't going to fix it:
SQL Server 2008 R2 SP2 buildnumber: 10.50.4000.0 or 10.52.4000.0 ?

So ignore the numbers and follow the steps in the article given in the link at the end of the article.

Sue