Poor Service in preparing service

On 24 September I had the misfortune of going to OB Cradlestone Mall. This was because they took 30 minutes to prepare sushi dishes for my wife and son and 40 minutes for a platter for me which i consider deplorable. When I confronted the manager, Peter I was told this was normal and that HO is OK with that and that it can take up to 90 minutes sometimes and on top of that he tried to palm the fault onto the waiter for not telling me it would take that long. When I contacted customer service, Tatenda rep**** to me saying that because sushi is 'art' it can take up to 30 minutes for this to be prepared. In all my visits to other OB I have never waited more than 15 minutes and so Tatenda's response and Peter's service fly in the face of every principle of customer service. I told Peter that I was tipping the waiter as normal because it wasn't his fault but it was indeed management's fault by not ensuring that that an environment with enough suitably trained staff was not available to be able to provide the expected service, that is what management generally does. All in all, in 24 hours Peter and Tatenda have managed to lose a client of the last 15 years.