diff --git a/Api/CalculatorInterface.php b/Api/CalculatorInterface.php
deleted file mode 100644
index b953676..0000000
--- a/Api/CalculatorInterface.php
+++ /dev/null
@@ -1,30 +0,0 @@
-<?php
-
-/*
- * @copyright Copyright (c) 2021 mash2 GmbH & Co. KG. All rights reserved.
- * @license http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0).
- */
-
-namespace Cobby\Connector\Api;
-
-use Cobby\Connector\Api\Data\PointInterface;
-
-/**
- * Defines the service contract for some simple maths functions. The purpose is
- * to demonstrate the definition of a simple web service, not that these
- * functions are really useful in practice. The function prototypes were therefore
- * selected to demonstrate different parameter and return values, not as a good
- * calculator design.
- */
-interface CalculatorInterface
-{
-    /**
-     * Return the sum of the two numbers.
-     *
-     * @api
-     * @param int $num1 Left hand operand.
-     * @param int $num2 Right hand operand.
-     * @return int The sum of the numbers.
-     */
-    public function add($num1, $num2);
-}
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e69e442..2f835af 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # CHANGE LOG
 
+## 2.4.9
+- Bugfix | Improved error message for show duplicate attributes options
+
 ## 2.4.8
 - Bugfix | DEV-72 replaced deprecated ZendHttpClient with CurlClient
 
diff --git a/Model/Calculator.php b/Model/Calculator.php
deleted file mode 100644
index 22edfc8..0000000
--- a/Model/Calculator.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-/*
- * @copyright Copyright (c) 2021 mash2 GmbH & Co. KG. All rights reserved.
- * @license http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0).
- */
-
-namespace Cobby\Connector\Model;
-
-use Cobby\Connector\Api\CalculatorInterface;
-
-/**
- * Defines the implementaiton class of the calculator service contract.
- */
-class Calculator implements CalculatorInterface
-{
-    /**
-     * Return the sum of the two numbers.
-     *
-     * @api
-     * @param int $num1 Left hand operand.
-     * @param int $num2 Right hand operand.
-     * @return int The sum of the two values.
-     */
-    public function add($num1, $num2) {
-        return $num1 + $num2+4;
-    }
-}
\ No newline at end of file
diff --git a/Model/Entity/Attribute/OptionManagement.php b/Model/Entity/Attribute/OptionManagement.php
index 56547e1..0f1b1a1 100644
--- a/Model/Entity/Attribute/OptionManagement.php
+++ b/Model/Entity/Attribute/OptionManagement.php
@@ -54,8 +54,9 @@ public function add($entityType, $attributeCode, $option)
         if (!isset($label) && strlen($label) == 0) {
             throw new InputException(__('The attribute option label is empty. Enter the value and try again.'));
         }
-    
-        if ($attribute->getSource()->getOptionId($label) !== null) {
+
+        $optionIdByLabel = $this->getOptionIdByLabel($attribute->getSource(), $label);
+        if ($optionIdByLabel !== null) {
             throw new InputException(
                 __(
                     'Admin store attribute option label "%1" is already exists.',
@@ -70,6 +71,39 @@ public function add($entityType, $attributeCode, $option)
         return $this->retrieveOptionId($attribute, $option);
     }
 
+    /**
+     * Get option id by label
+     *
+     * @param $attribute
+     * @param string $label
+     * @return null|string
+     */
+    public function getOptionIdByLabel($attribute, $label)
+    {
+        foreach ($attribute->getAllOptions() as $option) {
+            if ($this->mbStrcasecmp($option['label'], $label) == 0) {
+                return $option['value'];
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Multibyte support strcasecmp function version.
+     *
+     * @param string $str1
+     * @param string $str2
+     * @return int
+     */
+    private function mbStrcasecmp($str1, $str2)
+    {
+        $encoding = mb_internal_encoding();
+        return strcmp(
+            mb_strtoupper($str1, $encoding),
+            mb_strtoupper($str2, $encoding)
+        );
+    }
+
     /**
      * Save attribute option
      *
diff --git a/composer.json b/composer.json
index 68a6dff..ded40c7 100644
--- a/composer.json
+++ b/composer.json
@@ -1,7 +1,7 @@
 {
 	"name" : "cobbyio/cobby-connector-magento2",
 	"description" : "This extension for Magento 2 provides a direct integration of the cobby management methods to your Magento 2 shop.",
-	"version" : "2.4.8",
+	"version" : "2.4.9",
 	"type" : "magento2-module",
 	"require": {
 		"magento/framework": "^102.0|^103.0|^104.0",