FNB unable to link vehicle finance to my banking profile

I recently purchased a vehicle through Toyota Financial Services (a division of Wesbank). The account shows on my banking profile if i log on via the website but not on my banking app. My private banker has tried tirelessly to get someone to assist but FNB and Wesbank IT departments have now thrown their hands in the air and say that the problem must be with my app. I have even tried uninstalling and reinstalling the app. My second issue is that, although i can see the account on the website, i am unable to transfer money into it. I have never had this issue before and nobody, except my private banker, is interested in helping me.