Where did my data go? Oh there it is

So this has happened this whole week and I can't handle it anymore.<br> <br> Every day I put airtime on, R12-R50 and buy myself daily data + night bundle (R17ish)<br> <br> I try to keep enough airtime for the next day but during the night, around 2:30 I get notified that I have no data / airtime - out of funds.<br> <br> I use the *141# USSD and low behold, still 800mb of my night bundle left but no airtime.<br> <br> With the remaining nightly bundle I get disconnect every 30-60 mins.<br> <br> I can't go on like this.