Washington's roofing and contracting

Paid this company $5,300 for a new rubber roof in 2015 that was guaranteed for 15 years, after roof applied it has been leaking since. This current-day all of my ceilings have leaks which have gotten worst each time it rains and I cannot get a response from the contractor to fix the issue. I have tried numerous times to get in contact with this company but still have not received a response.