MFC - deceased department poor service

Good day

I am struggling to get this problem solved any help will be appriciated. I bought a vehicle from a lady her husband passed away the vehicles natis papers still shows that its registered on mfc after 4 years. I have spoken and received all the documentation from the estate holder and that the estate is closed off. There are no money outstanding on the vehicle. According to mfc the natis papers was courier to the deceased in the 16th of may 2015 and he passed away on the 23 of may 2015. The vehicles licencse disc is bebind and so every month it increases. I will pay for the copy of the natis to be resend as we are not sure he signed for it but still will request a duplicate, after various conversations email, calls MFC will do an investigation this is taken almost 2 months now. I have forwarded all the paperwork all the letters requested. And nobody is getting back to me.