I am presuming that Orange have provided the connection through your exchange; it can take a few days to set up sometimes.
You could start by disconnecting all `phones and filters apart from the one to your PC. It could also be an idea to use the primary socket to the property in case there is a problem in the other wiring.
If you can then connect to the ISP check all filters and reconnect them and the `phones one by one to see if there is a problem there.
If this is satisfactory you may need to try your connection on other sockets and see if they work. If so it is something to do with the one you were connected to in the first instance.
If you can`t connect from the primary socket then you may need to contact BT for a line check.