Does the starter motor and ignition need to be changed at the same time?

I have a vauxhall astra 2001 1.7dti and it would't start no clicking or anything. A garage said it was the starter motor and it would be £200 to fix, so he did it. Went to collect and said because there was a new starter motor it need a new ignition or it could burn out as it was old. however he said he wouldn't charge as it was his mistake. Having just been to collect someone else said the ignition was already burnt out when his gone to change it and the spring had broke? Being a woman and not understanding I am guessing it wasn't the starter motor to begin with? As surely he would know that if the starter motor goes the ignition needs to be done at the same time??? Please advise!