Rain deductions after cancelation

I have been with Rain for a few years now even though there wifi signal hasn't been all that great. At times there'd be no connection for 4 days on end. Due to this ongoing issue, i decided to get ftth and cancel my rain. I called rain on the 23rd August requesting a cancelation of my services. I was told by the agent that i cannot cancel during the month and that i can only cancel it on the last day of the month.

Another agent contacted me a few minutes later and confirmed my cancelation, of which i requested a cancelation letter as prove of my cancelation.

I received my letter and the connection was no longer available on the 31August.

On the 1st September rain debited my account, i then contacted rain and was told that my money will be paid back in the next 7-14 working days.

Im disappointed in how quickly you decided to deduct money that was not even owed to you, you deducted money from me the very next day knowing very well that my services were canceled.

So why must i wait 7-14 working days for you to pay my money back that you "mistakenly" took!!!