Any good maintenance company either leaves a 'report' explaining any chemical treatments (organic or synthetic) for the homeowner or places flags with explanations as to treatment. If your company is not doing this it is entirely proper to ask them to do so, and retroactive as well! If you are using 'Organic' you should never see FAST changes. There are synthetic fertilizer formulations that can approximate organic chemicals in the rate of release...extended release. Fast change is never good for plants.
Organics should not be more expensive. For 4 fertilizations per season (normal) with synthetic fast release, only 2 are necessary with organic. (Ask for or insist on Dr. Earth's Lawn Fertilizer or SIMILAR...amazing difference)!! Please remember chemicals are chemicals. Understand the difference before making this black and white...bad or good. If you are paying for 'Organic' you should be getting verification of what the crews do each and every visit! Even without asking for Organic, you should know every treatment, chemical applied!!
A lot of people think fertilizer as a pesticide. Nope. ALL gardens us humans grow will need fertilizer. All. We've disrupted any natural cycle so we can't expect to 'go natural' without failing. Now pesticides/herbicides are different. They are meant to KILL. Specific, non-specific, leaching, short life, long life, LD50...and on and on. To kill anything in the landscape you'd better be prepared for ramifications. Killing always, always causes problems! It is never a solution! You HAVE to be educated and licensed. If the individual doing the application has none, then there HAS to be a supervisor that has a special license to be supervising laborers.
You can demand that your company produces evidence of licensing. Any company using chemicals HAS to have a Pesticide Applicator license!! And if they have this they know they are to give notice of what they've used and where. This is a big deal!!
Using any pesticide/herbicide is akin to putting a bandage on an problem that could/should have been prevented in the first place!! Even not on an 'Organic' contract this is first and foremost the basis of a knowledgeable, licensed and reputable company.