No Delivery after 3 months following upgrade - No one to assist after escalating to numerous channels

My dad upgraded my mother's phone end of June already (Acc ********** ). The phone was supposed to be delivered 3-5 days after, and to date, STILL NOTHING. My parents have contacted MTN call center on numerous occasions, they've also been to various MTN stores, and no one was able to assist on just informing them as to when the phone will be delivered. They are however already paying the upgraded monthly fee, which includes fees for data etc which they are not even able to use since they are unable to access internet or any apps with the current phone. Since then, my parents have sent numerous mails, and so have I. Every time we just get a reply to say it's being escalated, but still............NOTHING. The email addresses this has been escalated to is: ********** - ********** - ********** with various ref # ********** 0 & ********** 6 & ********** 4 - and we have even followed the complaints procedure, this was about 2 weeks ago already, and not even a reply on this. No one stays within their SLA's, where is the pride? So ideally, they have been paying for a contract AND a phone which they are unable to use. I'm sure another provider would've welcomed them with wide arms. Where to from here???????????? We are expecting this to be resolved soonest, and for my parents to be credited for the 3 months of poor service, 3 months of not having a contract phone, and 3 months of not being able to use the services included in the contract.