Legal Question About Deductions Made From Production Occurring Prior to Ownership

I acquired a set of producing minerals in Texas with an effective date of June 1, 2011. Subsequently, Chesapeake began paying royalties for production beginnign June 1, 2011 and continuing onward to the present. In a recent check statement, CHK made a series of deductions for royalties from production dated March 2010-December 2010. I called CHK to get an explanation and they said that they overpaid the previous owner of the interest that we acquired for the production from March 2010- December 2010, and that since I am the current owner, I am responsible for that overpayment which is why they deducted the overpayment from my account even though I wasnt the owner of the interest during the dates that were re-stated. Does anyone with legal expertise have an opinion about whether I have a leg to stand on here?

The language in the Deed used to convey title to the interest to us, the grantee, includes the following:

"The grantees shall have, receive, and enjoy the stated undivided interest in all bonus, rents,
royalties, and other benefits which may accrue to the mineral interests
conveyed to them by this instrument, from and after the Effective Date, as if the
respective grantee had been, at the date of making any currently valid and
subsisting lease, the owner of the conveyed mineral interests. Without limiting
the foregoing, the grantees shall be entitled to their respective share of production from the Chesapeake Energy –X pooled unit beginning with production at 7:00 a.m. on the
Effective Date."

I'd say there's a better chance that you have a claim against the party you bought it from. They're the ones who benefitted from the overpayment and you have a direct relationship with them.

To start, you should look at the lease to see if there is an offset right against subsequent owners. The deed does not amend your contract with Chesapeake.