Telkom penalises for migration even on month to month contracts!

I took out a 30gb + 30gb contract with Telkom, I specifically took it on a month to month contract, with no device, in order to be able to cancel or change my package without any penalties or device fees. I recently change my contract to a 10gb contract, and now I'm charged over R400 for migration fees. What is the purpose of having a month to month, if they are going to charge anyway? This seems *******. I've tried logging calls with Telkom, and sent various emails, and nobody seems be even trying to assist or have a look. I only get a generic response "When moving from a higher package to a lower package you get charged migration fees even though there was no device included".