Poor customer service

So I've recently purchased an item on Takealot, it had been sold out for a while and when they finally restocked, to my surprise it had even had a discounted price. Score for me! or at least that's what I thought.. A day went by and I got a notification indicating a delivery delay.. Another day another notification.. Day 3 I get an email stating that they had to cancel my order due to incorrect pricing.. I tried looking for a customer PR contact to speak to about the matter but I could not find anything. I saw on Facebook someone said they got hold of them via facebook messenger so I thought I'd give it a shot. Still nobody has gotten back to. I went back onto the site on the 21st of April and saw that the item was still at the marked down price at which I purchased it (I purchased it on the 19th of April)

I think it's extremely unprofessional for a site who is known for good deals and marked down prices to tell a customer that they are canceling an order because of Incorrect pricing. And then days later it still was not corrected.. I checked it today out of curiosity and suddenly it's marked up by R200 which is now even more expensive than the original "normal" price.

What a Terrible experience.

If, for example, I am in a supermarket and I see an item displayed at a price, regardless of the reason, me as the customer will still get the item at that price. However this is online and there's no customer interaction so I am unsure as to how to handle this. What is the solution to this?