Consistently lagging in delivery

We had a long and frustrating move from Telkom to Vox, firstly the porting of our number took a lot longer that what was explained to us and secondly the Vobi app (VoIP app on your cellphone) is far from a replacement of your Telkom land line. We gave in and ordered a Supaphone (VoIP handset) and made it very clear that we are frustrated and in a hurry (we are using the phones for business). 5 days later we receive an email saying that they want our tax clearance certificate. First of all, why do they need this, and secondly why not ask for it earlier?