MTN's after sale service is nonexistent!

Hi, I need assistance urgently. My mum took out a Mobile contract. On the sale call my mum asked the agent if she could use a Sim card from a different service provider on the phone along with the contract Sim card. The agent said she could, when we received the phones we realized even though they are dual Sim only 1 port works. We called the customer service line and asked to port over the number that we needed, we were told the systems were down and we should dial in a few minutes and wait on the IVR queue to go to a different agent and hopefully their system is working. So we did. The second agent we spoke to said we can only port a number if we go into a branch and we will be charged to port the number, very frustrated at this point we decided we would go into a branch when we can.

This month my mum transferred less than R30 less than what her MTN debit order was going to be so unfortunately it was declined. She received an sms to say pay online or visit a branch to pay. She decided to go to a branch as we had still not received assistance to port the number. She visited the Phoenix Plaza branch today at approximately 12:30, she asked the man assisting her if she could pay her bill as the sms stated she could at any branch. He was very rude and abrupt and said their systems were all down, so she asked if she could pay in cash. He said no. She was upset but still asked if he could assist her with the porting of the number, he said he had no idea who would say that it was possible to port a number to an mtn Sim card and he also said he doesn't know why the customer care call center for mtn keeps lying to customers that it's possible to port. She explained that she took the phone only after being told she could use her Sim card on it with the contract Sim card and since it's not possible she now has no choice but to port the number. The guy said he can not and mtn will not port a number for her, but did say if she could provide her documents he could apply for a new contract for her and port the numbers when he is processing the order. I find this very odd considering he said his systems are down for payments but he is able to process a new order for a contract for her and secondly it is extremely strange that he can port the number if she agrees to another contract but can not if she already took a contract with mtn.

What is the way forward? This number needs to be ported as the "dual sim" with mtn is not a dual Sim as one would expect.