Bad Service dilivery recieved from Xchange Investments

The lady by the name of Thando sold me a software from xchnge investments and told me that ill receive the best customer service, to my surprise i am still not happy with the treatment I got from them and when i went to her as she was the sales person she told me to contact Keith who will assist me but till today no one has came back to me and both of them no longer works for the company I need assistance with cancellation of the loan as the services where not rendered.I was given an email sales@xchngeinvestments.co.za to sent a cancellation letter and I did but no one responded now im being ghosted.Kindly help me to resolve this dispute. I also spoke to Kenny ,Goerge,Linda,Anna and Mavis whom didn't seem interested in helping me.