Bounced cheques and recovery of the money from a customer

Hi,

I had received cheques from my customer out of which I deposited 8 cheques in the bank last week and all of them got returned in 1 day.

I am trying to call the owner and accountant of the company but they are not replying or answering my calls now.

I know they are here in the UAE. So how should I proceed with the complaint and what do I do to recover my money?

And as my total 8 cheques have returned, will it affect the customers' account? I had heard that if 4 cheques get returned the account is blocked.