Prepaid seating given away

I prepaid for my Seating & selected seats when reserving my tickets. When checking in 24 hours before the flight, it showed no seats allocated and I was unable to select a seat. Eventually phoned Kulula to find out that my seat booking in row 2 had been changed to row 9 but was originally row 2. I was unable to make any changes online due to the prepaid seats, and neither was the call center. Bad service, why give away prepaid seats!!?? Booking ref : INBMRS