We need information as to software or a service.
We need to setup a 24/7 technical support line but fear it will be abused by non-customers calling at all hours.
Therefore we'd like some solution where we can limit who calls, we thought maybe a PIN system that each client is given a PIN (then if they abuse it we can reference to who owns that PIN) and if you don't have a PIN, our phone doesn't dial and the system hangs up on you.
Maybe there is a better solution already out there but you get the idea hopefully.
Please bid to either provide us a solution or information to a currently existing website/software/tutorial.