Used less but charged more

I have just sent the following email to Eskom customerservices

I fail to understand why when I use less electricity in the December to January period compared what I used in the November to December I get charged more. For November-December I used 496 and was charged R672.07 for December-January I used 478 and was charged R916.13

When I compare the meter readings that I sent to you with those on the statement they appear to agree. So why the extra charge?

Where did the 68 days that appears on the current statement come from? We are working on an approximate 30 day period. I have had invoices and paid on a monthly basis, so now why suddenly 68days?

and in reply get told this department only opens on 1st March

Thank you for your email, kindly note that the Eskom email service channel is temporarily unavailable and will resume on 1st March 2018.

they probably think that by then I will have forgotten about the matter