Disgusting customer service

I was referred by a friend to attend a seminar or whatever timeshare sales pitch it is. I was contacted by Michelle***) on WhatsApp. I responded and advised I would be able to attend on 11/12/2019 at 6p.m. I unfortunately worked late missed the pitch and had other things to attend to so it slipped my mind and I never advised her I could not make it. I was what sapped this morning and again due to work I was unable to respond immediately only to be sent a rude and childish WhatsApp from Michelle who continued to tell me of my behaviour and even swearing in her WhatsApp. I was disgusted as for a company that relies on referrals it was unacceptable for her to engage a client potential or otherwise like that.