Is this ridiculous or not?

Well, if in 4 months you've done nothing else wrong, you must be mother Theresa, because, that's not even close to possible for me. Assuming that you truly have done nothing wrong, and that they aren't the type to hold a grudge, I would say that perhaps your actions really hurt your stepmom. That maybe they still hurt. Maybe she feels like you hate her. Maybe there are small things you've done since then that even though you didn't mean for them to, made it seem to her that you hate her, or your dad, or that you simply haven't learned your lesson.

So, go to them. CALMLY, respectfully, and as peacefully as possible, APOLOGIZE. Tell them how sorry you are for your actions 4 months ago, that it will never happen again. Mention that you are trying to work on your temper or your language (whichever one was the most hurtful) and mean it. Really work on it. Tell them you are willing to work toward getting your privileges reinstated (and maybe talk a little on how you understand that they are privileges and you are grateful for them) But then ask them to please set a limit. Tell them you are truly sorry, but you are also very bored, or ask them specifically why you can't get a date on when your grounding will end. Ask and make sure it's not something you've done since. Don't get upset if they can't give you a date right away, or can't tell you why they haven't set one... keep your cool and ask them to please really think about it.

The result of all of this is that you will show yourself to be mature, responsible, and show that you see how your actions affect others. This will look good for you to them, and probably get you an end date for your grounding, and being that mature and responsible and apologizing may end your grounding all together. It may even make your relationships with them a little better.

Your statement of " I think the real reason is because they are too lazy to talk about it! " sums it all up. You have a disrespectful attitude and your parents know it. They probably will give a end date when you act like a nice person with out the attitude.

It looks like u messed up pretty bad anyways i think u r still grounded because of ur attitude i mean even though u didn't do anything bad they r still not convinced that u r sorry for ur behavior, u need to show them that u r good kid and start by apologizing to her even if u don't really mean it deep in ur heart. Xmas time is perfect to get this over with and start fresh

you probably have a little attitude.

sit down and talk to them about it. say i'm sorry, i've learned my lesson, etc. that's probably what they're waiting for.

say sorry and you might get it back or save up and get your own stuff and own place like i did

yes it is fair. you're a brat. you should apologize.