Nightmare with Nissan Sa

On 3 May 2019, I contacted Nissan Springs and received a quote of R4,600 for a rear bumper for Nissan Qashqai. I paid the full amount and advised the parts would be available in two days for delivery. Quite shocking the opposite was true I have not received the parts till today. Nissan misled and deceived me as a consumer advising that they ordered the parts from Japan. When I lodged a complaint the story changed. I was requested to either pay R11,800 or take a refund. How unconscionable can this conduct be?? What a shame to Nissan brand