How ethical is the management of Harties is Africa?

On 14/06/2021 I made reservations for me and my children for accommodation at Harties is Africa for the night of 25/09/2021 ( Reservation NB-67413107). I fully paid the reservation on that same day.

On the 14/09/2021 I got an email from Harties is Africa that they cancelled my reservation because there was a dispute between them and my sister.

The irony of the whole thing is that the reservation my sister made had nothing to do with me and my reservation so why victimize me? She only contacted them in August or September to make a booking for herself (Booking NB-67955454).

I do not have nothing to do with the dispute between Harties is Africa and my sister and find it highly unprofessional from them to cancel my reservation.

They at least had the decency to refund my total reservation amount, but still inconvenienced me as I can now not get any accommodation on that weekend.