MTN billing date change

I've been with MTN for over 12 years and I've never had a problem with my payment date, note I'm informed that every single month i have to phone in and make a payment arrangement to pay on the 26th of the month because MTN have changed thier billing system and want me to pay on the 16th of the month, who gets paid in the middle of the month? Definitely not me. So every month my line gets suspended and everything month i have to phone to make a payment arrangement. I've never heard of anything say pathetic before in my life!!!! I'm very upset!!!