price changes

I bought a laptop on the 3rd of march and had a look at the Microsoft office software price but I told a sales person that I be back the following morning because I didn't have enough money with. He showed me that its R899 for 1 year and R1500 for the lifetime one. Then I went there this morning less then 24hrs they telling me all software prices have changed due to pretrol going up at midnight. WhenI asked for a manager he told he understands that I was there yesterday and the sales person who is currently helping has told me the prices that I budgeted but he can't do anything about it he can'tcontrol the petrol pprice there its not his problem. He do me a favour of giving me R50 off. I felf he didn't care of me as a customer and as it is my first time buying a laptop from them he didn't care about whether I come back or not. I feel cheated as I went back to organise money to buy the software then the next morning I told prices have changed. Now I can't use my laptop for the purposes I bought it for because I don't have the right software. I need to the higher management of the store to sort it out and should get the software with the price I saw it by. Or I need my refund.