Prime subscription should load automatically but it doesn't, why?

I received the free 12 month prime subscription but I only got the first months gig of 3gig (which had issues but I was happy because someone called and that was sorted promptly). Last month I didn't receive it and had to come here to complain about it and then I received the data. This month I haven't received the free data again. So now it seems like I have to come here every month to report the matter, shouldn't it just load automatically?This is becoming a nightmare. Can someone just please fix it.