in the user manual there will be part set/omit options/chime enable etc...
not all systems function in the same way, it wont be a pnel made by the company just one of perhaps 10 manufacturers, look on the keypad or control panel(big box) for an identifying number then search google for images, ceck honeywell's website theyre one of the largest, or ademco. how much control the end user has over part setting the system, omitting zones, selecting chimes etc is programmed by the installation engineer when fitting.
sorry to hear of your bad experience, but if i told you what i know about the security 'industry' and how customers are disadvantaged you wouldnt beleive me. Look on their headed notepaper to see if they are a member of a regulatory body/inspectorate, get in touch with them and CC your letter to the company, believe me, they wonnt like that since complaints management is one thing that can loose them there accreditation.
20 years fitting security systems, now run own business - and not fitting systems that dont work or overcharge customers. (UK), i believe the phrase in the US is "start kicking ass and taking names"