Mid cycle fees

What is going on with mid cycle fees? Has it always been like this? It seems like every other new BAN we sign up is getting charged for 2 months of service within 5 days of activation. For example we signed up a customer on 11/13, and he got a bill for 11/13-1/13 due 1/6, how is that even “post paid”? I myself ordered a watch on and was billed an entire month before I even received it?