@ChemikaWale Thanks for your suggesstion. We have done this for BVN verification. However, it turns out that a lot of people did not provide email addresses when registering for their BVN. We are currently exploring Robo-calling and USSD.
For SMS OTPs, we are working on a permanent fix.
Thanks @kolade. Wema Bank is the parent bank of ALAT. However, as will become obvious in a couple of days, ALAT is an independent proposition from Wema Bank.