What is the customer id of the customer who has filed the most recent complaint?
select customer_id from complaints order by date_complaint_raised desc limit 1
What is this customers city?
select t1.town_city from customers as t1 join complaints as t2 on t1.customer_id = t2.customer_id order by t2.date_complaint_raised desc limit 1
How about their phone number?
select t1.phone_number from customers as t1 join complaints as t2 on t1.customer_id = t2.customer_id order by t2.date_complaint_raised desc limit 1