Mtn bad service

I am a cutomer of mtn for 12 years now.the service i am getting the past year is patetic.i upgraded one of my mtn contracts and received a Oppo phone .i told the oppo rep that i need a dual sim phone because i need to use my vodacom sim because i dont have mtn network coverage on the farm.he told me no prob. Just remember the phone is network lock for 12 month..i waited my 12 month and phone in 10/23 to unblock the network lock.i phoned 135 and the gentelman that help me said no prob the wil sent evething thru to the tec guys and within 5 working day my vodacom sim will work .from oktober 23 i have phone in al least once a weak because my phone was still network lock .the person that helped me on the phone told me no prob wil sent it thru to the tec guys .within 5 working days network lock will be gone .6 months later nothing has changed .still network lock.i have many ref numbers .and even ask to speak to a supervisor the told me the supervisor will phone me the same day before 17:00 .im still waiting for them to phone me .they expect people to pay the debit orders each month but the service is so bad i dont even want to phone them anymore for the problem.today is exactly 6 month for a problem that was surpose to be solved within 5 working days...