First and foremost, slow down and take care when describing the problem. If you think that you're "lost" and "don't know much about it", imagine where I sit.

You've compressed a history of struggle with finding the right connectivity for your remote site AND a very loose description of the current setup and trouble ALL IN ONE LONG SENTENCE.

Please don't be put off; I'm not mean...just frustrated because I'd like to help.

Won't you try again, please? Start by naming the gear that's involved. It sounds like your phone system (what brand?) uses some kind of analog service to connect to the remote site. Are you sure that these are POTS and not OPX circuits? Also know that when phone guys talk about "tie lines", we are referring to a specific type of service. Non-phone people often use that term to broadly describe any number of possible voices services that might "tie" your two sites together. And while I understand all that, it doesn't change the fact that I need to know WHAT is broken before I can help you fix it.

I'm also wondering how the VPN plays a role with the voice piece, if at all. For all I know, you're IP-encapsulating voice with a MultiTech box and sending it over the LAN. On the other hand, you might be using the VPN for your computer network only.

"Press play and record at the same time" -- Tim Alberstein