Telkom apparently cancelled my internet account..

Hi, on the 31st August I went to telkom in hatfield and I asked to downgrade my 4mbps line to 2mbps and I asked the lady who was helping me to sign me up for the 2mbps Internet as well and it was done, I got the sms with my login details, I asked her about the billing, because Telkom bills in advance she said I would be credited in my next bill because I was downgrading, everything was working great up until today, my line is still 4Mbps and my internet is not working, I tried to login in their website and it shows that my account doesn't exist