Just how arrogant can a supplier be?

I am shocked beyond belief. It is now 20h43 in the evening. I just got an sms from Telkom inviting me to change to e-billing. Cool. Given the number of ****s and spams that do the rounds via sms, I elected not to respond to the sms. Maybe it was just some **** notification looking to see if my cell number is still current. So I called their 10210 number. Not only is Telkom arrogant enough to assume that they can engage my cell number, not my landline or my mail box, to invite me to change to e-billing. They are arrogant enough to send me the sms after 20h00 in the evening when their 10210 number is not attended! I am so sorry. This is WRONG! How dare this supplier be arrogant enough to contact me about a change in our relationship at a time when they are not available to attend to my call. Mr Telkom... If you give a continental at all for your clients, please have the grace to man your call centre in the same hours that you send notifications to your clients. You are profoundly sick when you refuse to extend the same grace to your clients that you extend to yourselves. I do expect a response to this. IF YOU DARE TO BILL ME FOR MAIL, I WILL REFER TO THIS COMPLAINT!