bad service, no response to calls, prescription applies and no updates

I have been trying to get a hold of Vodacom since lockdown began. I have viewed my credit report and am listed for a little more than a R1000. I would like to challenge this listing as I am not aware of this debt, also no one has called me about this bill. it was listed in 2006, so prescription applies. I have made contact with experian to no avail, as well as vodacom. Please assist me urgently.