OP - Was this a refundable fare basis?

If so, why haven't you simply initiated a chargeback through your credit card issuer (bank(? This should all have taken 5 minutes:
1. Call and ask.
2. Wait 3-4 days.
3. Initiate chargeback
4, See credit appear on your statement.

Depending on your issuer / bank this may still be available to you. Legally, you only have 60 days and you have let that run. But, some issuers permit more.

As a general matter, this is faster & more effective than a lawsuit because it takes less time and the funds are yours sooner.