In April 2009 I decided not to renew my annual lease on my boat slip and advised the marina. I asked them if they would consider a month to month until I was ready to move and they agreed. In September I went back in because they were over billing me above the quoted amount and they made a billing adjustment. On December 30 I moved out and advised the marina in writing that day. They responded saying I owed the balance of the year because when I was in their office in September they advised of this and he had it in his computer notes. I never agreed to anything but a month to month and have never signed anything. Am I liable for the extra four months ?