Inherited Mineral Rights - Lease activity - No Royalties Paid

I inherited mineral rights in the Permian Basin in 1987, leased them in 2005 and again recently.

With the Wolfberry play heating up, being curious, I began looking at lease and production records (P4) on the Texas RRC website and discovered that there are 4 wellbores on the property, none active presently. But some show activity as late as 2001, delivery to pipelines (100% take) and salt water disposal. I did not receive any royalties or fees for the activity.

I contacted the Texas RRC about two months ago and have not received any response, neither did I expect to. What do I do now, contact a lawyer? Or have Statute of limitation run out? Would fraud be involved?

Any advice would be appreciated.

Thanl You

There is a four year statute of limitations on collecting back royalties in Texas.