No Stock No Feedback

Last week Thursday we made a payment from Nedbank to Nedbank for a cellphone that we got a quote on (Samsung Galaxy A5) Yesterday (Sunday) we went to collect the phone then they told us that they have to phone headoffice to confirm the payment but they cant do it now as they are closed on Sundays ,but why couldnt they check themselves the payment when i was in the stores as they do have access to this. Today when i phoned they confirmed that the payment is reflecting and told me to come and collect the phone , then 5min later they phone me back to say oh no i cant as they havent got stock and they are waiting for stock from clearwater. This is really rediculous. If you quote on n certain item surely you should inform the customer whether you have stock or not. The service is unacceptable and pathethic