vodacom incompetence

Well its the new year and once again voda**** decide to mess with me. I paid my account on the 31st of December in full only for them just like last year threatening to cut me off, so I called their rude call centre and after 10 different people threatening me I think I have had it with them , funny thing is if I call their collection department I am not even allowed to speak to a consultant because I don't owe any money according to the system and customer care threatens me saying I do, now they expect me to pay for a bank statement as proof why does this happen every year in January ? And why must I now incur costs for their incompetence