MTN DATA DISSAPEARS AND NOT GIVEN ON TIME

i HAVE 3 LINES WITH MTN - I HAD 6 GIGS AND IT JUST DISSAPEARED ON MY ONE LINE , i GET DATA WHICH I PAY FOR X 2 GIGS ON THE 22 OF EACH MONTH WHICH TODAY IS THE 27TH NOT RECEIVED NOR MY AIRTIME THIS IS ADDITIONAL DATA I PAY FOR , NO ONE CAN EXPLAIN WHAT HAPPENED TO MY LOST 6 DATA BUNDLE AND WHY I STILL HAVE NOT BEEN CREDITED WITH MY PAID FOR 2 GIGS AND AIRTIME - YOU EXPECTED TO PAY YOUR BILL ON TIME -My other 2 lines i lost 3 gigs and had to e mail them to ask where is my 1 gig i pay for per month and no answer to what happened to to my 3 gigs , 3rd contract no airtime received ,Its unaceptable that consumers just do what tehy want to yet you must pay