sim swap

i called mtn last week to do sim swap i passed all question and i was instructed to switch off the phone for 24hrs with i did it did not bring my number back it kept original number of the new sim , called again to do sim swap and i was given same instruction i followed instruction but still was not done , i called again on saturday with new sim immediately after successful security questions i was told to switch it off i did as i was told but still my number is not back can someone check and help please your self service number 135 does not allow me that is why i call customer care i need my number back please assists . my old number is ***