VM has never had any competently delivered online sales or account management capability. Sometimes the chatbot will pass you through to a chat agent, but that seems to occur only when there's spare capacity in the telephone call centres, and is very inconsistent. Quite how any company can still be so resolutely fixated on 1990's service delivery I can't say, but VM don't appear to see any problem.
All of which means that your best option is to phone up, deal with VM's dreadful telephony until you can speak to a sales agent.
