Fix my billing

I dont know whats going on but my billing sinces last months keep increasing.I was offered family package for R200 for 3 months i took it in April this month is last month.From last month my balance was R308 i paid 220 because i know its my last month.Today it says i owe R404 due by 6th.I sent them a message on facebook they said they experiencing technical problem it will be fixed with 5 days instead its becoming worse