Black Friday Disappointment

I had app**** for a black friday contract on Friday 23.11.2018. I was on a call with the call centre agent for about half an hour. I answered all questions and was told I was approved for a contract of a minimal value of R 149.

Later in the day I had received a sms which said "Dear customer,Unfortunately your order has been declined during credit vetting. Regards Telkom Sales Team". Yet my credit history is impeccable. I had a contact with Telkom Mobile which came to an end in September 2018 and I had not defaulted on a single payment! My monthly instalment was of a similar value (R 139). I want to know on what grounds I was declined.. or if Telkom didn't have enough stock and just used my 'credit history as an excuse'.