Property [] does not exist on belongs to many pivot relationship

I can't seem to be able to get my pivot relationships when using a belongs to many relationship! My structure looks like this

user Model

class Users extends Model
{

    protected $table = 'users';

    public function contacts(){
        return $this->belongsToMany('App\Models\Contacts', 'user_contacts', 'user_id', 'contact_id');
    }

}

contacts Model

class Contacts extends Model
{
    protected $table = 'contacts';
}

user_contacts Table

id | user_id | contact_id
1  |       1 |        1

users Table

id | Name 
1  | Jim Bliggs

contacts Table

id | Name       | Telephone
1  | Joe Bloggs | 0 111 1111

I can save using the relationship fine like so

$user->contacts()->save($newContact);   

But whenever I try to get all the contacts for a user to loop through them like this

$users = Users::all();
dd($users->contacts);

It just returns

Property [Contacts] does not exist on this collection instance.

Sorry if its a simple question, but I cant understand how I can create using the relationship but i cant read?

via Chebli Mohamed