Online purchase a nightmare...and Woolworths dont know how to help

Tried to do a purchase via the Woolworths App. Keep getting an error when trying to pay with ny store card. Called Customer service...spoke to 4 different people and NOBODY knows how to help. The error was logged and then got an email to state case closed, problem resolved....This is now Two days later from making calls and being put on hold as Woolworths dont know what happeneing.