There was a large error in my favor in a lease I signed and that was fully-executed. In good faith, I have agreed to sign a new lease because I know what I agreed to pay. I discovered this error in my lease when I went to pay my rent online for the month when the new lease goes into effect. Someone in the management company at some point must have realized the error, created a new not fully-executed lease with a much larger but still incorrect amount, and entered that new amount in the system, overcharging me. When I realized something was wrong with the rent amount, I contacted the office. After numerous back and forths, I was told that I signed a lease with the second amount and they could not change a fully-executed lease. Subsequently, I referred back to the actual fully-executed document which is in the system and I forwarded it to them. My question is - do I need to sign a document acknowledging that I am agreeing to void the old lease and if so what should that look like? Is there a name for a document like that? If signing a new lease is all I need to do, then that's great but I don't feel very good about this management company.