TallAdam85 said:
do i have to pay since i am renting
It depends on the terms of your lease and laws of your state. The lease can not override your rights under the law.
There are a few problems here. Did you report the broken seat? Or just try to fix it yourself? If you let them replace the seat, they may have seen the crack and replaced the whole toilet. If your lease required you to report the broken seat and you took it on yourself to fix it, you may have assumed the liability for any damages caused during the repair.
Sure, you did not know about the crack. But neither did they - unless a previous tenant reported it and they did nothing. So lets say they claim you negligently broke the toilet when replacing the seat. It's now your word against thiers that the crack was there before.
Make sure you clearly understand both your rights and obligations under the lease. Except for emergency repairs that have to be fixed immediately, put all requests for maintenance in writing and get a receipt for it. And report everything, even if minor, because you will have to pay for it when you move out.
Send the landlord a written notice of the need for repair and get a return receipt from the post office. If they try to make you pay for the replacement of the whole toilet you have to decide if it's worth fighting. You will then need a lawyer.
I am not a lawyer but I do own rental property and worked for a property management company. All leases that I have seen require the tenant to report all damages immediately and in writing. Also, the tenant is usually held responsible if further damages were caused by thier delay in reporting it.
In this case, the crack not being reported when it happened caused a worse crack. What could have been a less expensive repair has now led to a more expensive replacement. The landlord can liekly argue that you are responsible for the most part of the damages as it was your failure to follow the terms of the lease that delayed the repair.
I'm not saying it was your fault, because we do not know all of the circumstances. I'm just speaking hypothetically as an example. But in the future, protect yourself in these situations before they happen.