VODACOM AT IT'S BEST

Good day to all out there, I have just had a very interesting conversation with a VODACOM consultant, after I paid my account up in full my service was switched on after a huge fight that went quite high up in VODACOM, now I receive an invoice for my lines, I have been charged for March which is correct as well as April, I have not used the phone for the whole of April, we are only on the 5th of April, why must I pay for April when I am told the April invoice will be sent in May, are VODACOM going to expext me to pay for April and May in May, WHAT A *******.