Complaint

I have been with rain for more than 3 years recently I upgraded my package to a new one ,the router was delivered i July and it started working on the 1st of july I was debited twice whe I called to enquire I was told the previous subscription was on a post plan hence I was debited twice.I then verified if it will be cancelled and it was confirmed that it was cancelled and I will notbe debited twice in August tomy suprise August 1st I am debited twice and when I call to enquire I am told the same story of a postplan payment how do I get debited twice for a package tha was cancelled in July and pais for because of a post plan. I can not be paying for 1 subsription Twice .I need my money back .Icommunicated timeously for the cancellation of the first subscription and it was confirmed it was cancelled how do I then pay for it again with the same reason of a post plan