VVM consultants have no respect to customers

I have a big problem with a company called VVM Debt Collector, on the 8th of April 2019 between 15:00 and 15:30 pm a lady who did not me tion her name called me with regards to my African Bank loan, I told her to call me after 6pm because I was busy at work. She then insisted to Speak to me and I told her to respect me as a client she started swearing at me using a strong word (**** you) and then she hanged up. I feel abused and disrespected because this guy's even called me @ 20:45 pm last night while I was sleeping with my family. According to my knowledge a customer cannot be contacted after 8 pm. Please help as VVM keeps on abusing my rights in a country where I should be free.