The best method is to first contact TM. Ask them for a timeline. If they exceed that timeline (make sure you keep any correspondence record Eg email, live chat screenshot, case ID), then you will proceed to complain to MCMC @ https://aduan.skmm.gov.my/Complaint/AddComplaint?NOSP=1 There you can attach the case ID from TM and all the supporting information you saved. With all supporting documents, you will get prompt action from TM within 3-5 days. I did this for two of my accounts and both got upgraded finally.

At MCMC complaint website, choose the following options:

Can provide source that confirms this information?

Thanks for the heads up.