Boiler flush

Hi Recently had new boiler install on 25th June, I was told I would get a new boiler wireless thermostat and system flush, i asked the fitter if he had flushed the system and put inhibitor in the system which he said he had. I checked the system water with fernox test as i had my suspicions it had not been carried out but he had signed the manufacturer's book as it had X100 and X300 done, i complained to the company and now this fitter wants to come and run a cleaner through the new boiler and he says it will not.affect the new boiler but having been lied to once don't want to take any chances any help would.be appreciated