Landlord lease typo... still good?

.k sorry this if this is long but Im just trying to give you the whole story. o.k I live In Minnesota and I went to resign my lease for my appartment and I got a letter saying rent was going up to 520 a month. So I called and old then get a 11 month lease set for me and id be in some time to sign it. so I went in today to sign the lease and notice for the rent rate it read 495 insted of the 520. She went over the lease with me, saying how much it would be after this date and then I signed it and so did she. I then asked for a copy. I got a call from them saying I had to come and resign cause they notice they made a mistake and rent cant go that cheap. I told them well I have a copy call who you need to call im not signing it. and they said I had to and then they called me back saying they found another mistake saying they wrote in the wrong security deposite price. but I had paid that 2 years ago so they said it was voided casue there were 2 mistake on it... so is it still valid???