Avatar resize and delete

I'm trying to resize avatar but it's don't work. I'm using intervention/image package. Avatar stores but its stores in original sizes and when i update avatar old avatar is not deleting don't know why ( so what's i'm doing wrong?

   public function avatarUpdate(Request $r)
    {
        Storage::delete('users'.'/'.Auth::user()->avatar); 
        if ($r->hasFile('avatar')) {
            $thumbnailImage = Image::make($r->avatar);
            $filename = $thumbnailImage->resize(50, 50);
            $filename = $r->avatar->getClientOriginalName();
            $r->avatar->storeAs('users', $filename, 'public');
            $url = 'users/';
            User::where('id', Auth::id())->update([
                'avatar' => $url . $filename
            ]);
        } 
        return redirect()->back();
    }