prepaid line cancelled

we have a prepared line and it started not working since february, we phoned Telkom and we were told that all prepared lines were disconnected since February, to our surprise we were not told or receive a letter noticing us that prepared lines are no longer existing, we then asked that cant they open the line with the same number but we were told that we need to start from scratch which is impossible because we need that number since we have been using it for the long time - we have never had a problem with Telkom so something should be done urgently as this line is been used by elders who need it now.