I think you forgot that O2 won't lose that money because they never refund to their customers. But I might be wrong. So basically the clients lose the money. A

I think you forgot that O2 won't lose that money because they never refund to their customers. But I might be wrong. So basically the clients lose the money. Also average monthly can't be so high maybe you're including the device cost as well. Remember that many might have prepaid and no contracts.