INCORRECT BILLING ON FEB ACCOUNT DEBITED 31 MARCH

I have lodged an enquiry with Vodacom *** on 01/04/2016, after my bank account was debited with the February account on 31/03/2016. On 02/04/2016 a customer care consultant e mailed me a guide to Vodacom's billing, which FAILED to address my query as I enquired about an upgraded price packet which I purchased with effect from 01/03/2016 but which was billed along with my usual billing costs for February. Vodacom's customer care are apparently reading my subsequent e mails [according to \read receipts\" from my server] but to date nobody has even deigned to call me, let alone respond via e mail. I am not prepared to phone them again, to hold the line for 20 minutes of my precious time, only to be met with a consultant who advises me that they will \"look into it\" and revert to me via e mail [I took this road on 31/03/2016]. Shame on you Vodacom. How difficult would it be to explain to me why you billed the new price packet effective as from 01/03/2016 in February already??"