Refund from Booking.com

Strawberry26

 had to cancel a trip in April as advised by booking.com that we could not go as intended. Trying to get a refund. I'm NHS staff so was allowed a full refund after providing proof which I did. Still no refund and no reply. I want to make a complaint but I cannot do it on their website. No email no number. The property themselves forward my emails to them which they dont reply. Tried Twitter. Promised the earth moon and stars and still nothing. 
Can anyone advise who to make an official complaint to about this? 

Life__Goes__On

You need to  give more details about the trip