Bad customer service

I went to nandos at Boulders shopping center branch to have my lunch. The cashier who was assisting me at the till point was refusing that I buy becouse I wanted to sit and eat there but there was no space she said. I offered to wait and she kept on refusing and at the same time the cashier next her was helping and giving customers who came after me the numbers to go wait for the next available table. I questioned the fact that it was not a problem for the cashier next to her and she ignored me and started talking to someone behind me. I felt very stupid and I kept on talking to her and she was just giving body language and kept on saying aaaaih not even looking at me. I then said I was going to send a complaint since she seem to have no interest taking to me and only then she wanted to attend me. I am a loyal customer of nandos and my family like nandos and we make sure that we go to nandos every second week and this is what I'm getting in return. I will never go for nandos anymore. For ease of reference the cashier transaction is as follows: 107 Netsayi order number 424 date of transaction 05,03,2022