Airtime and data missing

Good day<br> <br> I have been usind mtn for as long as i could remeber it has been good since lately I started to expireince loss of airtime and data every time i recharge after a couple of hours i get a massage my data has been deplited and i have to recharge again this is frustrating cause alot of money is being spend on mtn i cant be buying data and aitime everyday, I used to buy data and airtime that would last me a month since im on prepaid now im scared to do so hence it will be depleted before i even use most of it. I really like mnt hence im been using it forever but by the looks of things i might have to port to another network provider since mtn cant deliver the service it used toooreally this is emotionally draining and i tried calling to complaim a couple of times but nothing is being done about this matter.<br> <br> Ta