MTN billing

I am with MTN since 2004, (Before that, Autopage, wich then sold to MTN). Since 2007, I am a cash paying customer. Every three or so years, they change their billing system. For 14 years I have been paying my accounts cash and were always in advance. December 2020, yet again, new billing system. Since December 2020 up till today, MTN is suspending my services monthly, and everytime I need to draw bankstatements for proof of payment!!!!

I did NOT change the system, YOU did!!! WHY must I now struggle because your system is faulty????? The excuse of "Cash paying Customers have 21 days to pay", is Bull!!!!! WHY, after invoice date, EVERY MONTH, my account is in advance, and after yor so called 21 days, I am 30 days in arrears? How in earth does your Maths work????? Get your act together, MTN, you are losing customers due to incompetece!!!!