Insert R data.frame into mysql table in mysql module REPLACE

Question

(Sorry if this is very simple, I just can't understand)

I have a table t sitting in mysql db that looks like this: (The name is the primary key)

Current table in DB

Name   Balance
 Bob      100
 Ted      150
 Carl     130

I also have data.frame in R reflecting modified balances

data.frame in R

Name   Balance
 Bob      90
 Ted      170
 Bill     50

I want to execute mysql replace equivalent so that my table is updated to reflect new balances

Desired table in DB

Name   Balance
 Bob      90
 Ted      170
 Carl     130
 Bill     50

I am currently using the RMySQL package - I tried to do this with dbWriteTable, but cannot make it work.

Eg1 ("Paste")

dbWriteTable(dbConnection, 'tableName', df, row.names=F, append=T)

Gives out

Name   Balance
 Bob      100
 Ted      150
 Carl     130
 Bill     50

Eg2 ("Overwrite")

dbWriteTable(dbConnection, 'tableName', df, row.names=F, append=F, overwrite=T)

Gives out

Name   Balance
 Bob      90
 Ted      170
 Bill     50

How do i replace?