public function getLastTransactions($limit = null)
 {
     $from = date(FORMAT_DB_DATE, time() - DAY);
     $to = date(FORMAT_DB_DATE);
     //die(returns($this->settings));
     $transactionDataObj = new SofortLib_TransactionData($this->_configKey());
     $transactionDataObj->setTime($from, $to);
     if ($limit) {
         $transactionDataObj->setNumber($limit);
     }
     $res = $transactionDataObj->sendRequest();
     if (!empty($res->errors)) {
         trigger_error(returns($this->errors));
         return false;
     }
     return $transactionDataObj->getTransaction(0);
 }