Chargify::cancelSubscription PHP Method

    public function cancelSubscription($subscriptionId, $reason = 'Canceling the subscription via the API. Requested by customer.')
    {
        $rObject = new stdClass();
        $rObject->subscription = new stdClass();
        $rObject->subscription->cancellation_message = $reason;
        $rObject->subscription->cancel_at_end_of_period = true;
        $r = $this->sendRequest("/subscriptions/{$subscriptionId}.json", 'PUT', json_encode($rObject));
        if ($r->getResponseCode() == 200) {
            return true;
        } else {
            if ($r->getResponseCode() == 422) {
                $response = json_decode($r->getBody()->toString(), true);
                throw new Exception($response['errors'][0]);
            }
            throw new Exception("Cannot cancel subscription. Response code: " . $r->getResponseCode() . ". Response body: " . $r->getBody()->toString());
        }
    }