There were rumors circulating on some other FarmVille websites that you had to spend at least $100 per month to get live chat. Those rumors are false. However, Zynga has made a statement via the Official FarmVille Forum addressing FarmVille Live Support. In this statement they confirm that you do have to be a paid player, although you do not need to spend $100 per month.

“Hey guys,Thought I’d chime in since live chat support has been a hot topic for the last couple days. In order to get live chat, you do need to be a paid player. You don’t need to spend a $100 per month to get live chat though–that is just a rumor. You are entitled to live chat support if you are paid player, but please keep in mind that this CS feature may not be available due to high volume.
More info added:

• There will always be email support. The news about email support going away is just a rumor.
• Email support is available for unpaid users.
• Email and live chat support is available for paid players.” (Source: Official FarmVille Forum)