MTN sharing person information

MTN recycled my number which I was still using for Whatsapp, the new owner of my number has now got access to my contacts! This person is harassing my contacts, if you block the number they then use another number! MTN is doing nothing about the fact of someone having access to my personal information. The said I must send screenshots to their customer care to see if they will open a case! I did not ask for them to recycle my number and allow some person access to my personal information! If this is ok then how many peoples rights are being infringed!