double billing for upgrading contract before 1st of month

I upgraded a contract on 30.1.19

Now you charge for a device subscription fee for January AND February = only 2 days in January I was not warned about this Nowhere does it warn about you double charging on your website

What about the remaining previous contract already paid for the whole month of month of January?

So you have now billed double device fees for 2 days

This is blatant theft and ********** double billing

I demand this be reversed immediately