3GB of data in 40 minutes on a softphone call & can't load more data

Approx 3pm yesterday got on a conference call and within 40 minutes I had depleted all my data. I increased my limit and tried to recharge with 2GB of data which would not load. Called the call centre and was told it would be escalated. Heard nothing more. Called again around 7, was told there was an issue and that it could take 24 hours to load my data bundle. Explained that it's not good enough and asked to speak to the manager. Was told my data usage would be investigated but the only thing I can do for now is use out of bundle data and increase my limit. Explained this was not god enough and that I should at least be compensated with extra data next month to make up for it but was told that the manager was not around to authorise anything. I told her my contract is up at the end of Jan and if they did not make a plan immediately that I will be cancelling. She said she can't do anything so I have requested an investigation into my usage for the afternoon and a cancellation for end Jan. Logged on this morning and I had used 3GB in the space of 40 minutes on my conference call on my Soft phone (which would normally only be a few megs at most...) Absolutely appalled at the lack of customer care; if I had just been told I would have a credit n my account or some free data added then I would have been appeased. MTN are ******* and have no idea about service