Cancelamento de conbrança CHARGES API retornando transaction not found

Não consigo cancelar pagamento...

codigo para cancelar:

        $url = env("PAGSEGURO_ENV") == "PRODUCTION" ? "https://api.pagseguro.com/charges/$id/cancel" : "https://sandbox.api.pagseguro.com/charges/$id/cancel";
        $token = $pay_config->oauth_access_token;

        $data = array(
            'amount' => array('value' => $amount),
        );

        $client = new Client();

        $resp = $client->post($url, [
            'headers' => [
                'Authorization' => "Bearer $token",
                'Content-Type' => "application/json",
            ],
            'body' => json_encode($data),
        ]);
        return json_decode($resp->getBody()->getContents());

RESPOSTA:
Client error: POST https://sandbox.api.pagseguro.com/charges/CHAR_11326072-60DB-4855-82A0-72695A2BFF16/cancel resulted in a 400 Bad Request response: {"error_messages":[{"code":"14008","message":"transaction is not found."}]}

Estranho dar transaction is not found sendo que quando faço um get ele me retorna certo.