FNB Connect disappearing data

So after constant battles with MTN over disappearing data and airtime i switched to FNB Connect in November 2017. It went fine until i noticed on random saturdays the data would quicker that water being poured in a glass with holes in it but it's even gotten worse, i went from a balance of 1GB data at 10:30am to 167MB by lunch time with hardly touching my phone or using my data. Cellphone network companies in South Africa are all just the same, they're just her to spend our money and give us nothing in return. If you're thinking of changing networks you might as well stick to the devil you know as nothing changes with any of the networks