WMIC - change service user account

Hello,
I am trying to change a service from running under System Account to Domain User account.
I a running the following command:

wmic service <ServiceName> call change StartName = "<UserAccount@Domain.Name>" StartPassword = "<AccountPassword>"

I recieve "Succesful" notification but the command does not do what it suppose to do"

I value 21 instead 0.

Out Parameters:
instance of __PARAMETERS
{
ReturnValue = 21;
};

Anyone have any idea what is wrong here?