Hello & Welcome to Just Answer,
I'm Greg and will do my best to assist you in troubleshooting and isolating this issue today.
Sorry I didn't see your question earlier and to hear of any issue you are having with your phones.
To help you with this issue, may I ask:
1) The FULL Model Number of the phone system you are working with? If this is a cordless system, that model should be printed on a sticker on the bottom or back of the MAIN base unit.
2) What phone service provider (phone company) you have for this phone line?
3) Do you have ANY other phones (NOT part of the main system) attached to this same phone line and if so, are they working properly (good volume level)?
Please REPLY using the box below and the SEND button.
*** IMPORTANT NOTE: *** If you see ANY requests for "additional services" - such as a phone call - please understand that these are OPTIONAL and sent BY THE SITE AUTOMATICALLY (and not me), and I am NOT available by phone at the moment. Feel free to DECLINE (close) any such offers, and continue in this text/chat form.