code: public function deleteBlacklist($domain, $number)
      {
          if (!$domain)
              throw new BadMethodCallException('Parameter $domain is missing.');
          if (!$number)
              throw new BadMethodCallException('Parameter $number is missing.');
          try {
              $r = $this->delete('sms/' . $domain . '/blacklists/' . $number)->send();
          } catch (\Exception $e) {
              throw new SmsException($e->getMessage(), $e->getCode(), $e);
          }
          return $r;
      }
docs: Delete a number from blacklist
  
  @param string $domain
  @param string $number
  @return \Guzzle\Http\Message\Response
  @throws \Ovh\Common\Exception\BadMethodCallException
  @throws Exception\SmsException