It is a serious violation of AZ law to dispense bio-diesel above 5% without required notification on the pump alerting all users of the Bio-diesel and percentage of the content. AZWM is notorious for shutting station pumps down who violate this rule.
So, it is most likely that if there was no signs and decals at and on the pump at the time you filled your vehicle, the fuel you pumped was just diesel. I also seriously doubts a major chain would knowingly violate the law especially when it's a bugga-boo for state inspectors.
Could you have pumped diesel and sometime afterwards they got a shipment of bio-diesel above 5% and that was why there are bio-diesel signs now posted? Last year there was station near me that sold 110 racing fuel at a special pump, but one day they changed it to E-85R fuel; I guess all those racers who bought the fuel weeks ago were actually using E-85R and not 110 fuel because the sign now says E-85R!