Your ADSL service and Voice service, although on the same physical line, operates on completely separate channels. One operates fully independantly from the other.
Both services not functioning indicates a likely fault on the physical line itself, where the line may have a break in it, or a loose connection somewhere between the wall point, and the local exchange that manages the 2 services. Should both the ADSL and Voice services not be working, a fault will have to be logged to Telkom. This can be done via the Telkom ADSL Support centre, or, if Afrihost manages the line, can be done by contacting the Afrihost Support Centre.