Although it is true that approval of an account can be inferred from a party's silence if the account is rendered and retained without objection for a reasonable time after an opportunity to object, the cases standing for that proposition are distinguishable from the present case. See, e.g., Busch, 312 S.W.3d at 299-300; Dulong, 261 S.W.3d at 894; Palmer v. Kamin, 238 S.W.2d 216, 217 (Tex. App.—Austin 1951, writ ref'd). In both Busch and Dulong, each defendant signed a credit agreement, received a credit card, and made charges on the credit cards issued by each lender.