Telkom data bundles

Telkom changed there data bundles to 31days instead of 1 calender month. I bought the bundle in Feb and got message saying it will expire next calender month. Now did balance check saying it expires 1march instead of 1april. Checked there terms and conditions and there's no mention of this change and how can you change it once you have already bought it under the old calender month expiry. Telkom is commuting *****, obviously has a large customer Base now they feel they can make changes as they please without warning. Speeds have become snails pace as well during peak period despite having 5bars signal. What's going on Telkom, you running these customer fishing tactics with your competition deals and offering a pathetic service. I want my calender month data restored on my phone. I had bought a large amount of data for this reason. Once again the mobile operator gaining a fortune in revenue with this blow below the belt. I copy my message below I received when buying my data bundle Your account was successfully loaded with 2GB of anytime data and 2GB Telkom night surfer data that will expire at the end of the next calendar month.