Well, I worked in Signs4all 3 years ago. I knew how he dealt with the customers.
He tells you that he is going to install [X] product next Saturday, and everything is ready and on time. However, because he had a lot of late works. He doesn't keep his word. A lot of customers complained about his lateness. If you are going to make a business with him, make sure that you will have an invoice with the date of the installation. If he didn't install it on the time. You can file a complain with the consumers affairs.
If you Mohmed are reading this now (He is also knows as Abi), I still did not forgive you for the 20 dollar that you stole from my paycheck.