At the beginning of September I purchased a 1MB uncapped ADSL product from Openweb. I understood that the contract required a calender month's notice period. On 8 September I sent in a cancellation request (i.e. just about a week of purchasing the product). For around 80% of the time since commencement, the ADSL line speed was below 20Kb/s, which is less than 1/5th of the speed of what I purchased. At times it was so bad that even opening web pages took time. I know that there is nothing wrong with my telkom ADSL line as I also have a 1 GIG ADSL with another ISP which works just fine.
I've requested Openweb to waive the one calender month notice period as it means I will be tied in for another full month (October). I definitely cannot continue with such a slow ADSL service any longer. I will gladly pay a little extra for a 1MB uncapped line at another ISP. ISP's should not be allowed to get away with selling one thing and delivering something substantially below what they're getting paid for.
I really would not advise anyone to take up uncapped ADSL with Openweb (at least not on the same package as per my experience). It's really been a frustrating experience.