Throttling of connection

We have a 4mb line that has been working intermittently for a while now and since the weekend the maximum speed I can download at is 20kb/s which is absolutely ridiculous. I was told that a technician would call on Saturday to have a look. Nobody showed up or called. I then called the call centre last night and they explained that a certain amount of gigs is allocated to everyone on this 4mb line and once everyone(neighbours etc) uses the amount they begin throttling speeds. So apparently I don't need to use my Internet before it's throttled and to such an unrealistic speed. Why sell a data package as uncapped and then cap the speed? I believe that is not transparent business and kind of immoral. Having to go a week basically without Internet leaves a bad taste. All I can hope is that all resumes as normal next month and this is policy changed. At the very least a little more transparency in the way they conduct business. I would appreciate that. Also, since last night we have not been able to connect to the internet at all. The consultant I spoke to informed me that my internet would work only on 1 Feb again. This is not acceptable - I have to pay the full amount for the month