Disgusting, Appalling, Nauseating customer service

If you ever want to buy online from Sleepmasters, just remember if they are out of stock of something, they will let you pay first.... Then you will wonder why this specific item didn't arrive, so then you will have to be the one to make the effort to contact them, only after contacting them, they will tell you, it is out of stock. You will have to call and email them every single day for about a month, and they will tell you the same thing. Please note, they won't be the ones to contact you, you must do all the work. So then after a month passes, you will become frustrated, and request a refund, for this, you will have to call and email them too. After which they will tell you, your refund will be in by the Friday. They will even ask your banking details just for decoration. Friday will come and go, and they will be quiet again, so then you have to call and email again. 2 months will pass, and still nothing. 3rd month you will be so frustrated, because now it's not about the money anymore, it's the utter disrespect. You will turn into Karen mode, and 😑 not be as nice as before. You will start commenting on their pages, and they will tell you to check your inbox, until 3 months have almost passed, they will tell you that your refund will be paid in 10 to 30 days.

You have to mentally fit to deal with these people.

Their customer service is beyond appalling, they really don't care. My time, airtime, and energy was wasted on unprofessionalism.

How do I take this further? Any ideas?