I immediately returned back upstairs to inform a waiter who just looked bewildered and then shot off in the opposite direction as fast as possible. Within minutes the cockroaches had then dispappeared.
I got the impression that this wasn't a shock to them and probably not the first time they have had to deal with this problem.
There was no explanation, apology or even confirmation that this problem is being taken seriously.
Needless to say, I will never eat there again!!