Bad service

My account is always up to date,yet every few months my line gets cut,and because its cut,you can’t call even cell c to sort the issue out,how does that work? Than i end up going to a store which is a inconvenience,paying again just to get my line activated,so what happened to the payments I have made,I seriously don’t like my network,love my number though... And to top it of they will call and offer new contracts but cannot inform you if they can’t find payments on their system