Banking app doesn't work all of a sudden

My banking application has stopped working all of a sudden, sighting incorrect credentials after I've entered my pin.... The same pin I've used since the inception of the banking app, now all of a sudden yesterday afternoon whilst attempting to purchase airtime as I had an emergency to attend to and had no airtime.

My application refuses to take my credentials.... Like really now, why must I always have problems with this bank, why must a client struggle so much with such petty things.