Please can I remind everyone that you should never have a cold caller complete any jobs around your house and garden.  The usual scenario is that a price is agreed, which sounds very reasonable, but then the rogue trader find other faults and issues and this inflates the cost greatly.  They can then become threatening when questions are asked. 

Can I please ask you to remind any elderly or vulnerable family or neighbours about this.  If they are looking to get work done then encourage them to do the research or ask others they trust to recommend a company or tradesperson.