Finance department with accountants that can’t count

I signed a lease late in May 2018 where they were running a special to get one month free. I made a manual payment for some of May and the whole of June so July is was the free month and my debit order was to start in August. On the 1st of July, I was shocked to see my account was debited in full. I reversed the debit order with my bank as it was not what was agreed on. I then did decided to rather do EFT payments every month. When I was ready to move my belongings, I emailed 1 month notice and proof of payment on the 30th of April 2019 as I didn’t want to send It on a public holiday the next day. No one acknowledged my notice. Upon arrival at the facilities on the 1st of May, the guards advised that they couldn’t release my belongings as they didn’t receive a notice. After showing them the email and proof of payment, they allowed us to collect my belongings. The next day, I got a notification that my account was debited. A year later! Surely this is *****! Especially because I did not authorize the debit order, nor did they call me prior to *******ly debiting my account! I had never missed a payment so I don’t understand on what grounds they wanted to debit my account. About 3 weeks later, it looks like they managed to reconcile their books and only then acknowledged my cancellation without apologizing for **********ly debiting my account.