If you have a login but cannot change/manage any products or view bills/invoices, then you are an ordinary user. Only a manager or contract holder can view or change these things.
Check who the contract holder/manager is, and log into My BASE with that role. This person can then make the user an administrator.
Create a new login.
This login is now the contract holder/manager of the account. Once you have created this login, you have two options:
The number is now linked to the contract holder, and the user will be removed.