Advanced tree specialists

This person drops little green cards through doors calling themselves Advanced Tree Specialists. I called as I needed my garden to be groomed and treated, hurt my back so needed some help. Weeds everywhere amongst the flowers, lawn and pavements. He quoted me £100 for trimming my hedge, trimmed the weeds and using what he called an industrial strength weedkiller to kill all the weeds without wrecking the plants and grass. When I said the quote sounds pricy, he said it factors the cost of said weedkiller.
Well, apart from my hedge and a bit of strimming which took him 1.5 hours, I’m left with weeds some still afoot high, weeds growing like mad everywhere I look. No doubt he used water in his spray bottle. I feel an utter fool, and very reluctant to trust anyone again for garden help… an extortionate waste of money!