RSA Decryption JAVA BadPadding

Question

I am trying to integrate an API where I have to send the data in RSA encrypted and BASE64 encoded form. In response I get a BASE64 String which is supposed to be decoded and decrypted at my end. I am able to send the data in encrypted and encoded form. Also I am getting the response BASE64 String but I am NOT ABLE TO DECRYPT the string. In my decryption I am getting following error:

Exception in thread "main" java.lang.RuntimeException: javax.crypto.BadPaddingException: Decryption error

I have used following for encryption:

        String result=new Gson().toJson(parameters);
        byte[] cleartext = result.getBytes("UTF-8");
        PublicKey publicKey=readPublicKey(path);

        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");   
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);  
        byte[] ciphertext=cipher.doFinal(cleartext);

        String securePayload = Base64.getEncoder().encodeToString(ciphertext);

Parameters is a (String,String) map and I have put the parameters in it that are required to POST in the API. After encryption I am sending "securePayload" in POST request and in response I am getting a BASE64 encoded string which I am supposed to decode and decrypt. For decryption I am using following code:

public static String getDecrypted(String data, PrivateKey key)  {
    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

    cipher.init(Cipher.DECRYPT_MODE, key);

    byte[] dataArray=Base64.getDecoder().decode(data);
    byte[] decryptedbytes = cipher.doFinal(dataArray);
    return new String(decryptedbytes);
}

Above function I am using in following code to decrypt the String "data" which I am getting in API response:

    PrivateKey pvtKey= readFromPrivateKey("C:\\Users\\Administrator\\Desktop\\myPrivateKey.key");
    String result=getDecrypted(data, pvtKey);

To read the private key I have used following code:

    public static PrivateKey  readFromPrivateKey(String path) {

    String privateKeyContent = new String(Files.readAllBytes(Paths.get(path)));

    privateKeyContent = privateKeyContent.replaceAll(System.lineSeparator(), "").replace("-----BEGIN PRIVATE KEY-----", "").replace("-----END PRIVATE KEY-----", "").replaceAll("\\s+", "");
    System.out.println(privateKeyContent);
    KeyFactory kf = KeyFactory.getInstance("RSA");

    PKCS8EncodedKeySpec keySpecPKCS8 = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(privateKeyContent));
    PrivateKey privKey = kf.generatePrivate(keySpecPKCS8);
    return privKey;
}

Please help in the same. What wrong am I doing? I have checked that the Public and Private key pair used at my end is correct.