Wrong debit order

I had a contract with tracker which ended on the 8 March 2021 and i received a message that it will be a month to month contract hence it ended Beginning of April I called them requesting for a unit that has a panic button in order for me to press the panic button if i see something suspicious which is more convenient for women i was informed that they don’t that kind of a unit. I then looked for a company that will offer me the product I want for my safety i called them back after a week to cancel my contract the lady who was assisting me advised me that I need to give them a month notice what for because the contract already ended i do not have any contract with them so this business scheme went to my account to debit R734 I don’t know for what because I have the statement for the 18 of April i owe them R324.22 so I informed the lady I will pay it on their account month end of may i was surprised to see they want to ***** this amount of money from me and what for ? Because even if they include the month whereby they want me to give them notice it doesn’t get to R734 it should be R486 I want them to stay away from my account I will settle the R486 via eft because if it happens that they go to my account again to debit the amount that where is it coming from i will lodge a complaint with ombudsman .