Looking loony enough to shave her head encore, BRITNEY SPEARS freaked when she tried charging $5,000-plus for dresses, pants, shirts and accessories at chi-chi Hale Bob boutique in West Hollywood, and a salesbabe told her: “Sooo sorry, but your credit card has been declined, Ms. Spears!” SHRIIEEEEK!

Not about to abandon four bags of boutique swag, Britney snapped: “Run the card again!” But again… declined!

“Impossible! Enter the numbers manually,” insisted Bayou Bimbette. Again…declined!

Enter the boutique’s owner, asking if she had another card. “Britney, really frazzled, said she didn’t,” reports My Shopping Spy.

“She pulled out her phone and called fiance JASON TRAWICK’s cell. He didn’t answer, so she called his office – but his assistant said he was in a meeting. Britney screamed that it was an EMERGENCY! Jason finally came to the phone and Britney, almost in tears, cried: ‘I need you to come here right NOW!’”

Trawick raced to the rescue 20 minutes later, whipped out his own credit card, grabbed the packages and led Brit – now smiling like a little child – out of the store.