Is it legal for employers to make employees work 7 day weeks and minimum of 12 - 14 hours/day + no overtime?

I work for a well known and fairly new event company in Doha, that hosts international events, conferences, exhibitions etc. Us staff have just been issued new contracts with the same pay, befits etc, but stating that we may be asked to work 7 day weeks and on some days a "Minimum" of 12 - 14 hours on event days with no entitlement to overtime.
Our company is gearing up for a busy season in December and currently not so keen on employing more staff to complete tasks, but over-tasking its current employees. We believe these new contracts have come out to cover the company in case people complain etc...
The Labour Law states that a maximum of 10 hours per day and 25% overtime for excess hours worked, but I usually work 11 - 12 hours and at times up to 18 hours.
Is this normal in big companies in the country to exploit people like this?
Is there any institution we can turn to for help, without jeopardizing our jobs?
Hi,
Unfortunately you are not an exception, this happens country wide and well the bitter truth is that most of such violations is done only by the big organizations. The Human Rights committee themselves don't have sufficient rights I guess over here. My brotherly suggestion would be - find another job and leave the current company - I am guessing that might be you are not directly working where you are actually working. A middle company or organization is involved that is actually exploiting the rules.
best of luck