I would like to clarify a few points here:
1. The PR card I received in 2007 had validity till 2012. Not 2017. I was wrong about the year. This validity is what I am talking about when I stated above that my status is "inactive"
2. The SIN number I have right now is a new one, not the old one. I do not know if I had a SIN back then.
3. Paying domestic tuition isn't a prime concern, the main reason the renewal of my PR would help me is in my future and career.
Thanks for clarifying about the 2017/2007, presume that was a typo (it happens).
1. I believe the point made by someone else is that you can possess a valid card, or not, but PR status itself has no such concept - and what it does have is not linked (directly) to the card. Your PR card is not your status. There are only* permanent residents, Canadian citizens, and foreign nationals (a permanent resident is not a foreign national under law). So you are a PR even if you do not have a valid card. (Yes, there is more to this like a PR that is out of compliance with the RO, a PR who's been declared inadmissible, and there are foreign nationals with different status in Canada, etc., but those nuances are distinct from this classificiation.)
2. So the 'new' SIN you received is almost certainly a temporary one, the type given to temporary workers, students, etc. The question remains whether you got one when you were in Canada as a child - it is now basically standard practice to get one for children, since it links to benefits and some other matters, but before, this was less common (was seen as only related to employment). You should ask your parents if they ever got you one - if they did, it might make life substantially simpler for you. (I presume there is a way to request this if they know they got it but don't recall, but one step at a time).
3. That is good to know (and good for you in that you can continue your studies) - but it may be a useful wedge because, ultimately, if you can demonstrate to one level of govt you are a PR, you might be able to lever that elsewhere. And also save you some money - as a PR, you really shouldn't have to pay that.
I'm going to look, there is somewhere here info or a link to who must pay tuition in Ontario at domestic rates, and it's written somewhat differently than one might expect. Contrary to what one might think, the implication is that potentially one does not need a valid PR card for that purpose. I'll try to find it, may take a bit.
The SIN issue is related - and similarly a potential wedge - in that the law makes it clear that PRs have the right to work, period, and since a SIN is required to work, they can't deny you one. (I believe somewhere in the law or regs it's also the case that a PR should not work under a temporary SIN, that is, a SIN granted to a foreign national.) But the thorn for many in your case - Service Canada, at least in their offices, requires docs that you don't have (usually a PR card or recent COPR).
As I recall, someone here had success recently by applying by mail, after being refused at the Service Canada office. In fact it was a bit of a surprise as it was a non-event, they just got the SIN by mail after the normal delay of a month or so. And in your case, I believe that doing so would be beneficial for you and is without risk to your status (you have, by law, a right to work [as a PR and not just as a student], regardless of your compliance with the RO), as getting the SIN should not trigger anything at IRCC.
Have you spoken to a lawyer at all? Ritual statement I'm not a lawyer. A lawyer's services may not be free, but if you can get tuition at domestic rate, it would pay for itself (probably a couple times over).
*As far as I'm aware, in this context at least. I realize now that there may be some distinctions about certain Canadian/North American native peoples that I'm not well versed in, plus relation to the Indian Act, but I'm not even going to try to go there.
