Give users permanent level after x successful payments.

my_pmpro_after_change_membership_level.php

<?php

/**
 * Give users permanent level after x successful payments. (Fake "billing cycle limits")
 */
function my_pmpro_after_change_membership_level( $level_id, $user_id ) {
	global $wpdb;

	// change number of payments here
	$payments = 10;

	// are they expiring?
	if ( $level_id == 0 ) {
		// get old level
		$order = new MemberOrder();
		$order->getLastMemberOrder( $user_id );
		$old_level_id = $order->membership_id;

		// count successful orders for this level
		$sql   = "SELECT COUNT(id) FROM $wpdb->pmpro_membership_orders WHERE user_id=$user_id AND status='success' AND membership_id=$old_level_id";
		$count = $wpdb->query( $sql );

		// give them level back if they have enough payments
		if ( $count >= $payments ) {
			pmpro_changeMembershipLevel( $old_level_id, $user_id );
		}
	}
}
add_action( 'pmpro_after_change_membership_level', 'my_pmpro_after_change_membership_level', 10, 2 );