cannot uninstall exchange 2013

Hello all,

I had installed an exchange server 2013 (let's call it ServerC) on the side of my existing exchange servers (2 CAS, Mailbox in a DAG, serverA and serverB).

I had deleted the default mailbox database that came with the installation. There is no user nor database on this exchange serverC.

This said, when trying to uninstall, I get:

Error:
This computer is a member of a database availability group (DAG). It must be removed from the DAG before you can uninstall Exchange.

>Get-DatabaseAvailabilityGroup

Name             Member Servers                                      Operational Servers
----             --------------                                      -------------------
MY-DAG1         {ServerB, ServerA}

Also Cluster Failover feature is installed but nothing had been configured. cluster service is not running and still is disable from the initial configuration.

>Cluster Node returns an error, well it is not even running and the my cluster with serverA and B accordingly show the 2 servers and nothing else.

So Exchange uninstall thinks it is a DAG or Cluster but clearly it is not, where/waht can I look for and clear any settings to allow me to uninstall it properly?