Bad service

Bad service that I am receiving,I have being paying my account everymonth.my Internet router is R399pm.i ended up paying R1300 lastmonth.efter every payment next morning you find another outstanding balance .I kept paying until it all added up to R1300. Statement showing credited of R421.asked them to refund me .I was told.it no longer exist without explanation. they can refund me R194 I must send my acc and I'd copy. Which I did. Then my account was up to date.then.i thought ohk it means they have taken the money that I was credited paid my February R399. Then I woke up this morning I owe them R900.and I ask questions about refunds they said they don't owe me anything. my banking details that was send for refund they loaded them them , went into my account without my authorisation for debit order.they never fix having Internet router with them is stress. They lie.every agent comes with a different story.i have all records of our communication .statements and screenshot of theirs balance going up and down day by day. They are tiring