Frequently more than 24 hours of work

Hi good day. I am currently working in an IT company that has a bond of 200k as stated in training for work agreement that i signed 10 months ago. The training period lasted for 6 months as stated in the agreement and will end when we finished the training and will be hired as probasionary employee. But there is a clause in the agreement that we are commited to work for them for atleast 3 years and pay 300k if we did not comply. But this clause has supporting new contract for probasionary. Now, they give us the contract for probitionary after four months but the contract stated that it is signed on the 8th day of January which is a very big lie since they give us the contract last week of april. Now we work for the company for almost most of our time. We frequently served the company 25 hours or more without getting any sleep which is a bit risk to our health because of the loaded tasks that they give to us that is not feasible to be done to its given deadline and also because they require us to do so.One of my co employee raise this too much overtime work in our HR, but nothing happens. Now, I can't sign the supporting contract because I'm afraid of what is happening and because of the risk to serve them for 3 years in that kind of situation and because of the bond fee and since the contract is almost all about the companies benefits except the benefits that we have like sss,phil,health and pag ibig. and there is no other clause that clarifies the right of an employee like us, at the same time the contract did not break down the basis of 300k bond fee. If I will not sign the supporting contract, what are the possibilities that might happen on me? How can I fight for my health and my rights?