Oh yes, that billing system
Ex voda here
April came along and they decided that 25th of the month was no longer good enough to be paid on so they changed it, without notice to the 15th. I only noticed this because coming back from holiday the bank had kindly charged me 25 bloody quid for bouncing their DD and on the 18th texting to say they were restricting my service for non-payment and stiffing me for £4.48.
Talk to CS, very nice people to be honest, 'yes we have changed it back to the 25th and deleted the late payment.
May, same thing but I had not re-enabled the DD, 3 phone calls to CS
June ditto May
July ditto June and changed e-mail
August ditto July with I'll have my PAC if it's the same next month
September PAC code please
October you owe us £150 because you cancelled early
Tell you what you send me your bill and I'll send you mine .
Heard nothing yet.
I'd been with them for a decade without any issues, doubt I'll ever be going back.