FNB and Vodacom passing the buck between them leaving me in the lurch

I have been trying to make some critical payments through the FNB online baking system for which I need an Onetime Pin The pin only comes through an hour later by which time the transaction is void

I lodged an complaint with FNB and they responded that the problem is with my Cellphone service provider namely Vodacom In contacting Vodacom I was told the the problem is not with them but the bank

This is excellent, as it now leaves me with no solution and unable to make payments which is going to result in me defaulting on my payments and between them they are just passing the buck