Internet banking slow to fix error

I must URGENTLEY settle an account but an online banking website error make it impossible. I did send email to ********** but after a few hours there was no response and the issue persist. I must transfer funds to discovery health to Discovery listed account number. In the add beneficiary window, I choose Discovery health from the dropdown. The account number is filled in correctly. But when selecting "add", then the website give an error that the account number is wrong - the number they entered themselves