Can I Claim Overtime If I Haven't Gotten It For A Year?

I work at a small cafe/restaurant, and I work Tues to Sundays (including holidays) from 8am to 5pm. During most of the year, it has been really slow. There have been a couple of days during the year when the restaurant has no customers. However, now that it's "season time" where all the holiday people come to town, I am required to work from 8am. to around 9pm or 10pm every day for Dec and Jan.

The owner says I only get paid for the hours worked and don't get overtime, I didn't enquire about overtime sooner because I'm an idiot and should've realized sooner and was too afraid to ask in few of loosing my job because I really needed the money.

I also have no contract (all the workers here don't have one either), and we don't get payslips. A few days ago, I asked for my hours for the week, and they gave it to me in a 5 minute spread sheet with almost no information on it. When I worked out my hours myself, what they said I worked was around 10 hours lower than what I actually worked. When I asked for all my hours that I've worked there they said the can only provide for the last 60 days, and they will have to talk to their accountant, then the accountant will ask why and do an audit, my boss then said that the employees will have to pay for said audit, which doesn't sound right to me at all. He then said it's illegal for us to discuss our salary with each other.

There is a lot more I can say about the health and safety standards, but I don't think that'll be relevant here.