Telkom changed night surfer time to midnight

Signed a 24 month contract with telkom , approx 6 months into my contract telkom changed night surfer from 11pm to midnight which is a breach of contract, when I called and enquired I was told that was what was done and I had no say in the matter despite signing a 24 month contract with 10 gigs of data and 7.5 gigs fro 11 pm<br> I signed the contract based on the conditions and terms stipulated and telkom without consulting or mutual agreement changed the conditions which is grossly unfair and a breach of contract<br> This is pathetic that large companies do business with this types of ethics !!!!! Disgusting !!!