The Kemist interview questions

Despite the HR person forgetting and initially not apologising for forgetting our interview until I emailed them to which they scheduled an interview call for the next day. The in person interview stage I believed went well. They hired me for the position to which I was hired and invited an onboarding session for two days. Less than an hour before the first session, Sade cancelled and then for the second day it was informative. I was eventually sent the contract over a month later when I was meant to be sent but due to lockdown they were not able to have me start that week. Throughout the whole lockdown they did not send me the contract to review in the meantime despite sending an email requesting it to which she claimed she did not see my email. Eventually sent the contract after lockdown with a date to start and salary was negotiated then less than 24 hours before my start date I was sent a generic rejection email which was confusing. I sent an email asking for explanation for the sudden change to which they never replied. Absolutely disrespectful and incompetent practices.