Mtn
Dispute bill and nothing is done

Eceived a huge bill for my cell phone which was totally out of the ordinary and wrong. the main reason a single day of huge data usage. when i check my usage on my samsung for that day it shows that i did not consume anything close to the data amount that mtn stipulates. also as i have wifi and my phone is setup to use it and very rarely uses cellular data the bill cannot be correct. my monthyl bill is also very low and consistant so why did MTN not contact me when tehy saw a huge amount? call mtn 808 to dispute the bill and they say it will take 7 days to resolve. 8 days later i call as nothing is done and i am told they must log another call to dispute my bill as the first one was not logged correctly. what type of service is this? i asked what is wrong with the first call they logged and i am told that it was sent to the wrong department. how is that my fault? sort this out asap