Pathetic service

I ran out of data with the wifi .with a speed of around 15KB/s . Got 6 Gb and with in not even five minutes it was all gone with a speed of 15kb/s . I do not know what more to say and trying to cancel my contract you speak to somebody from MTN and "clap" the comms is down .What are they doing for their customer .Very disappointing of the service we use to get and years later we are just the golden goose ....