Despite the company's push toward modernization, the "Old Mobile" version retains a loyal user base for the following reasons:
The new Bet9ja is beautiful. But the old Bet9ja is practical. If you are betting in a rural area with poor network coverage or you are buying data by the MB, the old version is superior.
Try typing m.bet9ja.com into your browser. If you are lucky, it might redirect you to the classic view. However, most modern devices will auto-redirect you to the new mobile site.