Moved to OT.
This is ENTIRELY the wrong forum to ask about PBX systems.
I suggest contacting a telecom company that operates in your area.
I have a small business. There are ten employees working in my organization. Actually, Iím having 4 separate telephone lines which are quite costly for me and also Iím unable to control my staff because of communication problem. So I am planning to install a PBX system that I can save my money and time. Does anyone know a good source where can I buy?