Whatever the contract says will likely be what matters

But I thought ... bla, bla.
But it was my understanding ... yada, yada... 

Express contract controls over implied contract claim and claim that terms were orally modified where express contract contained integration clause and barred parol evidence inconsistent with the terms stated in the written (fee) agreement.   

EXPRESS CONTRACT TAKES PRECEDENCE  

"If the parties have expressly stated the terms of their agreement, they have created an express contract and are bound by it to the exclusion of conflicting implied terms." Malallah v. Noble Logistic Servs., Inc., No. 14-08-01030-CV, 2010 WL 343487, at *2, (Tex. App.-Houston [14th Dist.] Feb. 2, 2010, pet. denied) (quoting Emmer v. Phillips Petroleum Co., 668 S.W.2d 487, 490 (Tex. App.-Amarillo 1994, no writ)) (internal quotation marks omitted); see also David J. Sacks, P.C. v. Haden, 266 S.W.3d 447, 450 (Tex. 2008) (per curiam) (declining to hold that a written attorney-fee agreement which specified only hourly rates may be modified by evidence of an oral capping agreement).

SOURCE: HOUSTON COURT OF APPEALS - 14-12-00088-CV – 3/14/2013