MTN POOR SERVICE AND INCOMPETENCE

My retired parents who have had cell phone service with your company from the time your company started, were declined for an upgrade? They are in the middle to upper class of retiree's. No valid reason given. After numerous promises of " we will call you back" it has been 6 weeks still waiting. There contract has ended and MTN is still charging full monthly charges including the finance portion of the expired contract, surely that to is not legal!