Vumatel appalling service

I am shocked at the service from a company that is now trading as one but cannot get their act together between the 2 of them. I’ve been trying to get my fiber activated and the one thing holding me up is that the previous owner’s package was not cancelled by SADV(who were meant to cancel on the day mine was meant to be activated). I’ve sent proof of address but cannot get a resolution on this.My own service provider cannot assist much because Vumatel is the hold up. SADV and Vumatel are one company, how come it’s such a nightmare to get this resolved!