Cathay pacific unprofessional personnel

Unprofessional service from Cathay pacific crew by the airport, we've tried to allocate a seat online which is not applicable, so we call *** and the lady who answer the call said we can just go to the airport counter and tell them the preferable seats which we've told her, and we will be able to get the seat, and when we have arrived by OR TAMBO the counter man from B14 said there is no way he can do, how ridiculous is the service and we have been travel with Cathay pacific for more then 15years!!