My lease expired 3/31/11 but my landlord let us stay. In June I sent a vacate premises letter to move out in July, but July came and we let the landlord know that we were staying and she accepted the rent for July but told us we had to be out 8/1/11. We surrendered the premises 8/1/11 and did a non formal walk through. I tried contacting the landlord several times no response until 10/11/11 and she stated she is sending a status of deposit letter. 10/16/11 I received the letter and she is now stating that we are not getting our deposit back because we violated the lease for having a pet and the damages she has implied is not agreeable by us. She finally text me and said she is not responding to us regarding this matter any more. Do you think I have a case?

It depends on what state you are in. Some states require the letter stating reasons for keeping deposits to be sent within a certain amount of time. Some states also have double or triple damages for illegally kept deposits.
Yet I know people who still never got their money back because they didn't want to pay for small claims, win, and still not be paid. It can be tough be right.
(Did you have a pet that wasn't allowed?)

Depending on your location, you probably have a great case.

Most states' laws require that the landlord either send the deposit back, or a letter explaining how the deposit was applied, within a certain time after you surrender possession of the property. Usually that time is 30 or 45 days.

If the landlord does not return the deposit or provide the letter explaining how it was applied within the required time then the landlord is not allowed to keep any of the deposit and in some states a judge may award you double or triple the amount.

Tell us where you're located and we can tell you the applicable law.

I live in GA, we received the letter today and she is a private landlord. She knew we had a dog and only now are we just hearing that we violated the lease which expired 3/31/11.

We did not renew the lease and she had us leave without giving the required 60 day notice. Now she is only stating part of GA law but not one part of the move out is in the lease along with if we violate the lease. She and her sister(acting property manager) over to the house and played with the dog and no mention to get rid of him.

The time frame for return of the deposit in GA is 30 days. Thee problem is the law only applies to landlords who have multiple rental units. Its not clear what rules apply unit landlord. But if the landlord paid the sister to manage the property, then the rule still applies

Also I found nothing on penalty for non compliance. I would suggest consulting with a local real estate attorney local housing dept.

You haven't said whether the lease had a pet restriction. It doesn't matter that the lease expired and was then extended. It doesn't matter who saw the dog. What matters is what is in writing. Despite the 30 day law, you may have a tough time in court. I've seen it, but in another state.

I am not unsympathetic, but I have seen (from my animals in an unused room) what can happen to a Stainmaster carpet when urinated on. It goes right through after a while and you may not even notice it until you roll it back. I know someone who rented a carpeted apartment that had just been shampooed, but when the smell became noticeable she rolled back the carpet and there was literally an eighth inch of urine over the entire floor. So.. if the lease said no pets and if your dog urinated in the house, I would expect a judge to bend the 30 days.

The lease did not allow pets. But I have met with an attorney about this and we are fine because she failed to respond to us with any damages within specific time frame. She also has a clause in the lease that states the Georgia law about the security deposit and if we do not receive damages or violations within 30 days she forfeits her right to withheld. So things are looking better in this.

I would agree that a judge might "bend" the 30 days, but not for this long.

The problem you have is you may win in court, but then you will have to collect.