"Moreover, as set out above, Mr. Bielfeldt voluntarily signed a waiver of his right to bring a claim against the Templetons based upon actual acreage. Therein, Mr. Bielfeldt expressly agreed that, in the event a later survey revealed that the tract contained less acreage, he would have no claim against the Templetons for any credit or reduction of the sales price. Waiver is defined as the voluntary relinquishment or abandonment of a known right or privilege. A party who, by express or implied waiver, has refrained from exercising or enforcing his or her rights in a matter may be equitably estopped from asserting a claim. Consequently, we conclude that Mr. Bielfeldt has waived the very relief he now seeks." Id.