307 ignition

Calling on any experts out there I bought my year old 307 in December , the indicator wouldn't cancel so I took it back to the dealer who after 6 weeks changed the comms 2000. They told me there was a call back for the steering lock which would be ordered and when it arrived I would be notified. I completely forgot about this until about 3 weeks ago (that's 5 months after they said they would order it)my 307 just stopped and all sorts of warnings came on the computer .It completely reset the clock, service miles and would not start again. There was a burning smell in the engine and the battery positive lead was very hot. I was towed to the garage and the engineer told me it is the steering lock /ignition unit which should have been changed had failed causing the starter motor being powered up all the time I was moving causing it to burn out, Has anyone else had a problem like this and does his explanation seem correct