Can a defendant file a motion to dismiss when a court date has already been set?

We are evicting a tenant in Connecticut for non payment of rent. We had a state marshall serve a notice to quit back in November and had to wait 30 days to file a summary process. After filing the summary process we and the defendant's attorney submitted information to the court and after a couple weeks a mediation was scheduled by court to February 15th. We could not come to an agreement during the mediation so a court date has been set to March 25th. On Feb 16th the defendants attorney filed a motion to dismiss because we sent a letter to the defendant/tenant on Feb 2nd that they were blocking access to the shared parking lot and were in violation of their lease. The attorney used this letter stating that since the letter we sent had the verb age "You are hereby given notice that in the future such violations may constitute grounds for eviction and your lease may be terminated'. The attorney states that the letter states that the lease is still in effect and voids the notice to quit