Bad Attitude-Lebo

I received an sms from MTN advising that I have started incurring cost from my usage limit. So I called Lebo @ 09:14 asking her how many smses I have to which she confirmed I have 269 expiring on the 08/11/2015. I then asked how come I received this sms. To my knowledge my package includes 100 free smses & 200 anytime minutes. So questioned my bill of R544 reason being I load an additional 500 smses when my 100 is finished. My free minutes are always carried over. Lebo was highly irritated with me & put me on hold for over 14minutes without saying a word until eventually cut the call. Just how bad are your services, MTN? If you do not value me as a customer someone else will. Plse may I know how did MTN get to that amout of my bill. Please explain??