I'm missing something again ...

I'm using `mcapi2` and can subscribe a user in a controller with little problem using the following line:

```
@response = @mcMailer.lists.subscribe("XXXXXXXX", "email" => @user.email)

```

However, when I try and update the user (having now gained their first name) using:

```
@response = @mcMailer.lists.update_member("XXXXXXXX", "email" => @user.email, "merge_vars" => {"FNAME" => params[:stat][:firstname]})

```

I keep getting the following error:

```
ArgumentError (wrong number of arguments (2 for 3..5)):
app/controllers/stats_controller.rb:135:in `upload'

```

I think I've tried all formats, but simply can't seem to get it to update the first name, so any help would be appreciated.

**UPDATE:**

Still having no luck.

I've looked at the mailchimp-api code and it seems to define as update\_member
:

```
def update_member(id, email, merge_vars, email_type='', replace_interests=true)
_params = {:id => id, :email => email, :merge_vars => merge_vars, :email_type => email_type, :replace_interests => replace_interests}
return @master.call 'lists/update-member', _params
end

```

And my code has been every possible variation of the following (well except the right one it would assume):

```
  mergeVars = [:FNAME => params[:stat][:firstname]]
  @response = @mcMailer.lists.update_member("XXXXXXXX", "email" => @user.email, mergeVars)

```

The mail chimp-api has the following before the def:

```
@param [Array] merge_vars array of new field values to update the member with.  See merge_vars in lists/subscribe() for details.

```

But I still have no idea where I'm going wrong.