Knowhow

Transit Bolts left in Washing Machine

My mother-in-law, who is in her mid 70's bought a new washing machine 26 Dec 2012. She requested that the old one be removed and the new one installed as part of the package. Washing Machine was duly fitted and KnowHow team tested machine on a cycle and informed mother-in-law all ready to go.
Last week there were problems with the machine and a Domestic Repair Centre engineer visited today. He promptly noticed the transit bolts had not been removed and therfore caused considerable damage. Also, to her shock, DRC engineer informed her she had to pay £85.98 and claim it back from Know How, despite the fact she signed up and pays monthly for the know How cover - explain that one ?? And what washing Machine engineers leave Transit Bolts in place ??