absolutely furious

for almost 2weeks now i have been trying to with phone calls upon calls to mtn trying to get someone to help me get my phone back wich i sent in for assessments for repair or replacement. phone went in on 19/01/19. according to repair centre a cr was given for a replacement wich i found out myself last week Tuesday. everyone either tells they dnt handle returns they dnt handle devices they will log a complaint or escalate it. but no one is giving me proper service. Monday (04/02/19) i was by supervisor that i wud be contacted on Tuesday for delivery arrangements... today is Thursday i have still not recieved that call and i have made phone calls to mtn yday n today thursday (07/02/2019). i am paying for a device i do not have. i am putting myself at inconvenience. i have to keep phoning mtn. today to i was told that i would recieve a call to sort this problem out and still no phone call. ive had it.