$campaignExtensionSettingService = $user->GetService('CampaignExtensionSettingService', ADWORDS_VERSION);
$campaignExtensionSetting = new CampaignExtensionSetting();
$campaignExtensionSetting->campaignId = $campaignId;
$campaignExtensionSetting->extensionType = 'CALL';
$campaignExtensionSetting->extensionSetting = new ExtensionSetting();
$campaignExtensionSetting->extensionSetting->extensions = array();
// добавляем телефон
$phone = new CallFeedItem();
$phone->callCountryCode = "RU";
$phone->callPhoneNumber = "+7 (495) 587-75-75";
$campaignExtensionSetting->extensionSetting->extensions[] = $phone;
$operation = new CampaignExtensionSettingOperation();
$operation->operator = 'ADD';
$operation->operand = $campaignExtensionSetting;
$operations = array($operation);
$result = $campaignExtensionSettingService->mutate($operations);
"+7 (495) 587-75-75" - [InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @ com.google.ads.api.services.common.error.InternalApiError.(InternalApiErro]
"587-75-75" - [ExtensionSettingError.PHONE_NUMBER_NOT_SUPPORTED_FOR_COUNTRY @ operations[0].operand.extensionSetting.extensions[0].callPhoneNumber]
Пробую разные варианты, может на тестовом акке вообще не работает ?