Johannesburg - “We won’t drop the charges against Grace Mugabe. We are frustrated and furious about the police’s handling of the matter,” says Debbie Engels.Her daughter, Gabriella, 20, says the Zimbabwean first lady hit her with an electric extension cord at a hotel in Sandton until her head bled. Debbie said according to police, a warrant of arrest would be issued for Mugabe, Netwerk24 reported. She had been expected to appear in the Wynberg Magistrate’s Court in Johannesburg on Tuesday, but did not arrive. She also didn’t hand herself over to the police. Meanwhile, it has emerged that Mugabe, who was still in South Africa on Wednesday afternoon, is seeking diplomatic immunity. Earlier rumours had suggested that she returned to Zimbabwe on Tuesday, Jeanelle Greyling reports. The Zimbabwean government officially informed the Department of International Relations and Co-operation in this regard."Her itinerary includes private business, but also participation in the summit of the Southern African Development Community and the bilateral diplomatic meeting being held in Pretoria,” a statement by the police ministry said. “The suspect stays in South Africa and has not left the country.”Also read: South Africa debating immunity for Zimbabwe first ladyMugabe was visiting her sons, Robert jnr and Chatunga, on Sunday when she apparently stormed into their room and assaulted Gabriella while her bodyguards watched.Robert apparently is studying architecture at the University of Johannesburg (UJ), but has never been seen at lectures. It’s not known where Chatunga is studying, but it is not at UJ.According to reports the two spend a lot of time clubbing and holding excessive parties. They apparently like to spend up to R6 000 on champagne. They were evicted from a luxury apartment complex in Sandton last month after a spat about girls.Some of the criticism levelled against them is that they live a life of opulence while most people in Zimbabwe live in abject poverty. Chatunga was fiercely criticised after he posted a video on social networks in which he bragged about his excessive lifestyle which included booze sessions at the most expensive nightclubs. People in Zimbabwe are especially furious at the comment he makes in the video. “Live your life and have fun.”In addition to the assault charge she is facing and her sons’ shameful behaviour, Mugabe is also said be paying R70 000 a month for their hotel room.Also read: 5 Times Grace Mugabe Got Violent While AbroadRobert jnr couldn’t care less about the fracas. On Tuesday, he posted a picture on Facebook with the caption: “They keep on talking, we keep rolling.” He removed the post after a flood of criticism.