help refund pensioner ripped off for a hedge trim

Im a friend that has been told a very sad story that of a 80 year old pensioner near me who has been charged over 600 pound by con men to trim a small tree and paid them cash that she had in the house they also charged her extra when asked if they would take away the remains of the trimmings from the tree..! To which have been left in her garden and have taken away with the cash Another example of sick individuals taking advantage of the elderly which is heart breaking i would like to try and get this lady some of her cash back if not all of it i have never done anything like this before but would love to help her if i can.