Disgusting service

i went in to the MTN Boksburg branch near the East Rand Mall today to query an extremely high cell phone account for the second month in a row. Before I upgraded my cell phone from an S4 to and S6 2 months ago i was paying R500 or so a month, never higher and since the upgrade i now get bills of R2000.00 and all is for data. When i explained what was going on I was told that its not MTN's fault and instead it is the phones fault (because Samsung charges me for data, note sarcasm) then I was told that its facebook and everytime one of my friends updates their profile i get charged data for that, never mind that data restrictions have been set on my phone for FB. When I asked if she could help with my google play because it has not worked since i recieved the phone but is charging me data she laughed at us and told me she doesnt know how to do that. We where then told that she doesnt want to deal with us and we must take our complaint to Samsung themselves and when I asked to speak to the manager she informed us that SHE is the manager! How can you employ someone that has no people skills as a manager? She needs to be dealt with, i will not stop here until!