they want extra well im up to date

last month i pay by accidently R200 on my Telkom account Instead of R100 i phone them can i Reverse the one payment the lady said yes no problem i ask will it Reflect on my account now i Resifted a sms and said i must pay R302 so i phone them so the lady said its Because i Reverse the Money but im up to date but still i must pay R302 so they make R202 extra well in up to date but