Vodacom bad service and lack of correct info

My husband has a pay as u go sim where he acquires talking points. He wanted to use his points so the lady at vodacom in canal walk advised that unfortunately it's closed he will have to come back.So a few days later he goes back .He decided to take the Samsung tablet as the person said it was R2000 but with his talking points he would then only need to pay R1000. We have 2 daughters so he wanted to buy an additional. But then it was offline so he could not complete the sale again. So he decided to try another store Sunday passed ie. Tygervalley. The manager then said no the price of the additional tablet is R2500 and not R2000 as advised at canal walk. So the manager then advised my husband to take the tablet she will find out and will refund him the money if so. Then he received an email to say sorry but the price is indeed R2500. So my husband went back to return the tablet as the same tablet is at Game for R2000.The manager on duty today refused and said there is a no cash back policy. But why did the manager on duty the weekend say he can be refunded???? This is really bad service and staff need to be more Knowlegable.It is not the customers fault if the incorrect info is givn