In BA customer control panel (CCP), after pressing Buy More Services on Home screen the following error appears:
System Error No access rights granted to method
On Account screen in CCP there is no Buy More Services link at all
CUST_PURCHASE_SERVICE privilege, that is needed for service purchase is not included in corresponding user's role
CUST_PURCHASE_SERVICE privilege to user's role. The absence of this privilege in role can be caused by manual changes or by some misconfiguration, which needs to be investigated additionally.