horrific service

why would i go through so much to ask for an outstanding balance and paying it and then get told that there is still an outstanding balance due, you said amount owing was R619.45 and i paid R620 and then today i get told that i still owe R116.30,where does that money come from because i will not pay it, i have settled my account with you and i need an up to date letter confirming i do not owe you, and to top it off, im told i need to contact Easton berry who have never contacted me and yet they are charging me for their services..........i need this sorted asap