Elderly and vulnerable people are being targeted by cold callers who jack up prices when it comes to payment. Thames Valley Police said that rogue traders have been knocking on doors across the region offering services such as tree cutting, jet washing driveways, clearing gutters or collecting scrap metal. They offer a price verbally before starting the work, but this changes when it comes to payment, with the contractor often demanding additional cash. Some victims will be seen as easy targets for repeat visits. A spokesperson for the police said in such situations they should be contacted, e…