Bad service/no service

My billing month run from the 20th to the 20th, and I noticed on 18 May 2015 that were were PSD Calls on my unbilled list from 3 April to 20 April, but these were included in my April 2015 account. I tried to phone MTN, and after numerous attempts and not getting through, I phoned them at 06h00 in the morning and got through. The lady informed me that there was nothing she could do until my May 2015 account is not billed, then I can ask for an itemised billings for April and May (which I will have to pay for and cost about R24 per itemised bill per month). Why must I pay for itemised billing if it is a mistake on their side and they have access to all this information. I checked my May 2015 invoice and these charges were included there. When I tried to phone them MTN call centre services were suspended because of the strike, so I sent an email to the customer care email address on 6 May - I received a response on 19 May asking me to provide my ID, MTN pin, Address, Work tel no and bank name. Surely this is informaiton that I do not want to email to someone, I would have expected a call to confirm this info. Sandton City branch is pathetic.