Hello @sballabh 

If you have a wallsocket like this:

You'll need this connector:

You can call KPN customer service 0800-0402 during office hours to request one or go to a DIY shop and buy one (Say to the computer you want to speak to an employee).

In Dutch it’s called a ‘varkenssnuit’ connector.

What exactly is specified on the order confirmation?

If you have a pair bonding connection then the four pin socket should be replaced for a new connection which support pair bonding, for that you also should call the KPN customer service, tell them you have the wrong socket and ask for a mechanic to replace it.