MTN - customer care is a waste of time

It's impossible to work with MTN - I recently obtained a data sim on a 24 month basis. Every month I get 8/10 emails telling me my payment has gone through then telling me my payment hasn't gone though so that I never know what is going on. I've tried to access the MTN app but it tells me the number is "grey" and MTN customer care writes back to my emails which contain my account number asking me asking for reams of information including my pin which they tell you never to give out on their website. This is just a mess around service.