The function get_term_by() would allow you to get the taxonomy term name from the id.
$quantityTermObject = get_term_by( 'id', absint( $quantityTerms ), 'quantity_category' );
$quantityTermName = $quantityTermObject->name;
The function get_term_by() would allow you to get the taxonomy term name from the id.
$quantityTermObject = get_term_by( 'id', absint( $quantityTerms ), 'quantity_category' );
$quantityTermName = $quantityTermObject->name;