Booked a flat and cancelled it the next day

Hi, I had booked a flat, but the next day requested them to cancel it the next day. They did not process my cheque. But after a month, they are sending demand letters for the amount (they are presuming I already paid the booking amount which I did not because they did not submit the cheque). I have sent them a mail complaining about it, they have replied in the mail that there is no problem, kindly ignore. I also talked to them on phone and have a voice recording of several calls where the confirm that they would remove my name and I would not have to pay anything. Can they still sue me for some money? I did not pay them anything and stopped my cheque. If possible, I will upload the booking contract, the screenshots of the mail and the voice recordings.