Lazada advertise product already out of stock.

Last monday already make an order with amount of RM5k+. The payment already made thru mastercard.
Then today (after 4 days of payment), lazada send an email to me mentioned the product is not available and they will refund my money.

After 4 day they want to cancel my order? Wtf??
They also already  remove the item from their website today?? Too late already... i gues im not the lucky one..

Further action in my mind:
1. Complain to tribunal - selling an item online  but they did not have item/product in hand. (I feel being cheated by lazada).
2. Complain to bank negara - how can this company been allowed to made credit card transaction from people without have the product that they advertise in their website.

This is my experience buying an item from lazada.