I just wish Vodafone could get their act together and make it possible to lump both my fixed line/internet and mobile bills into 1 account, it's a right royal PITA having to pay 3 different bills every month to the same company
CRM/Billing systems are massively expensive, not just in terms of capital to purchase them and install them, but due to the complexity of plans and offerings/bundles/promo's etc, and the effect it has on the staff in terms of planning and training.
Timing is absolutely critical, and any company after an acquisition will take stock to think about the next opportunity to merge systems. I don't think Vodafone has had the opportunity to allow enough time and capital to commit to such a change, but with Telstra-Clear there will be a new opportunity to take stock of company strategy and direction. They wouldn't merge two systems and leave a third out there, it has to be done once, and with the amount of planning this will take, it could be at least 3 years before we see the final result.