Failed purchase

I made an online purchase on the 27th of May, my order got cancelled on their app but my account was debited. I then called in this regard. I was told that they will credit back my money into my account by the 29th. On the 29th I called again only to be told they are still investigating this after been given an SLA of 48 hours. It's now the 1st of June with no progress and no feedback via email like I was promised. I dont know what's going on but its unacceptable.