company I invested refuse to pay back after note maturity

In Dec 2006, I invested $30k in a callable convertible note of a small company, which is due to mature in one year, in Dec 2007. At maturity date, I have the option to convert the note into company stock at $0.50 per share. Otherwise, the company should pay back my money with interest.

During 2007, the company went public on pink sheet list. But the stock price was below $0.50 around Dec 2007. I actually bought some stocks of this company at the lower price.

When the company asked me to convert after maturity date, I replied in email saying that I want to defer the decision for a month or so.

The stock price has become lower and lower since then.

Then around May this year, I emailed twice and also sent a certified letter declining the conversion and demand to have my money back with interest. The company simply responded with a letter saying the they cannot pay me back at that time.

Recently, I have talked over the phone with the CEO several times. He just ask me to wait one more month, and said the situation will become better. But refuse to promise me a pay back schedule.

According to some inside information, the company has many investors like me with the convertible note, but most of them did convert into the company stock. Only several people did not convert. Also the company should have enough money to pay back my money right now. But the situation could get worse.

Now what should I do to get my money back? Should I hire a lawyer now? what else can I do before I hire a lawyer?

The company is a Nevada corporation, but with headquarter in Indiana. I am in Texas.

Many thanks in advance.