Blank information after merge

Question

R version 3.2.1

I'm following this article on how to create Heat Maps and downloaded the required files (just need help with the logic)

This works

setwd("D:/GIS/london")
library(maptools)
library(ggplot2)
library(gpclib)

sport <- readShapeLines("london_sport.shp")

When I run

names(sport)

I get normal output, i.e.

[1] "ons_label"  "name"       "Partic_Per" "Pop_2001"  

And when I print sport

print(sport)

I get this (showing first 6 lines)

                                   geometry ons_label                   name Partic_Per Pop_2001
0  MULTILINESTRING((541177.7 173555.7 ...))      00AF                Bromley       21.7   295535
1  MULTILINESTRING((522957.6 178071.3 ...))      00BD   Richmond upon Thames       26.6   172330
2  MULTILINESTRING((505114.9 184625.1 ...))      00AS             Hillingdon       21.5   243006
3  MULTILINESTRING((552108.3 194151.8 ...))      00AR               Havering       17.9   224262
4  MULTILINESTRING((519370.8 163657.4 ...))      00AX   Kingston upon Thames       24.4   147271
5  MULTILINESTRING((525554.3 166815.8 ...))      00BF                 Sutton       19.3   179767
6  MULTILINESTRING((513062.8 178187.2 ...))      00AT               Hounslow       16.9   212352

So far everything looks normal. I understand the next few lines, to create plot points

p <- ggplot(sport@data, aes(Partic_Per, Pop_2001))
p + geom_point(aes(color="Partic_Per", size = "Pop_2001")) + geom_text(size=2, aes(label=name))
gpclibPermit()

Then we make the shape file (sport) into a data frame

sport_geom <- fortify(sport, region="ons_label")

And when I execute head(sport_geom) I get

      long      lat order piece group id
1 541177.7 173555.7     1     1   0.1  0
2 541872.2 173305.8     2     1   0.1  0
3 543441.5 171429.9     3     1   0.1  0
4 544361.6 172379.2     4     1   0.1  0
5 546662.4 170451.9     5     1   0.1  0
6 548187.1 170582.3     6     1   0.1  0

Then the command to merge data, where the problem arises

sport_geom <- merge (sport_geom, sport@data, by.x = "id", by.y = "ons_label")

When I go according to the document and print by., the only values that pop up are by.data.frame and by.default

And when I execute head(sport_geom), the data is blank!!!

[1] id         long       lat        order      piece      group     
name       Partic_Per Pop_2001   <0 rows> (or 0-length row.names)

What am I missing and how to troubleshoot this?

Perhaps this is an error in the document (this is the simplest tutorial I can find on Heat Maps), because I was troubleshooting another error for the past hour.

Please help!!!!!! I know it's long, but it's the best I could do to explain the issue and possibly reproduce it.

If you need links to download the stuff, I'll get it for you.