Thank you for your response @Krista. I have only used one account since I agreed on a contract with Vodafone and I have the correct login details. In order to double check, I used the provided link and once I input the requested details, my email address appears correctly, so the issue is not my login credentials. Is it possible that we would need to recreate my account somehow?
I was able to verify my customer number from an earlier email regarding contract extension. Kindly note that I only receive SMS notification about the invoice, which directs me to the app. However as it was aforementioned, the app does not show correct information. The issue is the same through the Vodafone website.