Poor service

RMCS reduced my monthly airtime to R65 per month without my concern or even notifying me about the change, so strange my monthly subscription has not change i still pay of for the previous R135 monthly airtime. i have been calling them every week to fix the problem but what i am getting its reference numbers and the promises that someone will call me back. reference numbers ********** 099751, ********** 130465, ********** 146791, ********** 146776