Checkers online shopping

I am extremely unhappy with my first Checkers online shopping experience. I am a customer who spends roughly 10k a month at Checkers. This month I decided to try online shopping to minimize exposure during the pandemic. I bought goods to the value of 3k, the money went off my bank account instantly and the order was accepted. This morning when trying to track the order I discovered that the order has been cancelled. I also received an email to say that my order has been cancelled because it was more than 30 items and that I will receive a refund without 2-5 working days. Why did they accept the order if it cant go over 30 items? And why do I have to wait for my money? I am sorry but this is not on. You took the money immediately and I expect it back immediately. And to crown it all they do not have client service agents in the call centre during lockdown. I demand either my money back immediately or my order to be delivered. This is unacceptable service.