Rain don't refund even with bank statement proof

I've been with rain for over 2 years because their network never given me problems, my only concern with them is the billing team, they just deduct without updating their invoices, i paid an upfront fee of R999 before they deliver the router. they 1st charged me for 2 separate routers after their special was advertised for buy one get one free premium router, I went back and forth with them till they made it one installment. recently I skipped Feb 2024 payment which was suppose to be 1st Feb2024 they paused internet, I cancelled the account on the 23rd Feb they deducted on the 29th Feb 2024 full amount. and on the 1st March another deduction full amount R999. when i call to enquire they say i skipped January but i sent bank statement to show i paid early for January which was 30th Dec. and i also paid 1st Dec which is twice in same month.