Sends LOD without ever sending an invoice??

We had a geyser burst in a rental unit of ours in April 2015- Standard Bank Insurance Brokers appointed Domesticare or as they also trade The Leak Specialists. They came and repaired the geyser and i never heard from then again. Out of the blue 5 months later, I get a letter of demand from their debt collectors advising that i owe R250 - I called Janice immediately to query this - she then goes on to tell me that it was excess owing (which is normal with insurance claims) - this is really strange, because between now and april not once have i ever received a phone call, an email, a pop past, nothing to say we owed them anything. She then goes on to tell me its my responsibility to pay - how can i pay something i know nothing about??? She then admits that she had the incorrect email address that she was sending the invoice too? i asked her why she could not have the decency to give me a call - she said \I don't have time for that"- but she has time to authorise the debt collectors to send me a letter of demand?? very strange. Anyways"