cleanup-abandoned-signups.php

<?php

function cleanup_abandoned_signups($event) {
  $txn = $event->get_data();
  $user = $txn->user();

  // Count complete transactions and non-complete transactions
  $user_incomplete_txns = $user->transactions('`status` != "complete"');
  $user_complete_txns = $user->transactions('`status` = "complete"');

  // User only has non-complete transactions, so delete the user.
  if(empty($user_complete_txns) && !empty($user_incomplete_txns)) {
    $user->destroy();
  }
}
add_action('mepr-event-after-signup-abandoned-reminder', 'cleanup_abandoned_signups');