Truworths online bad service

I ordered a dress online at Truworths for R330. A day later I received an email that the dress is out of stock. I then went online to check the dress only to find there is stock for all sizes but the amount has gone up to R440. i then emailed customer services who then advised its not sold on line but in store only. i find Truworths to have handled this matter very unprofessionally, you could have just admitted you made a mistake on the price. What is the point of ordering on line if the price changes and then you are told go to the store. Im not sure if Truworths realises that you are competing with the likes of Shein. very upset with this issue.