Getting billed everything day with no explanation

I don't understand why I keep getting billed. I paid R625 last week Monday because I was calling an old router and buying 2 new routers. Than told my next billing will be 25th on this month and i will be billed for 1 router. Friday I was told I owe R35 because I had added extra gig on m 4g Sims which I paid and today R688 got deputed from my FNB account which I don't understand what is it for. When I call to find out they keep hanging up on me with no explanation.

Am getting but on hold so many times and after phon getting cut