No response for cancelling a registration

I am sponsoring a foreign student to study at a college in South Africa, and chatted to a sales consultant at Intec to make sure that it will be possible to enroll the student and that study visas will be possible. Firstly, I was assured that a study visa will not be required to get the study material and that we have 18 months to finalise the study visa. When I requested the letter to be used for the applications, the consultant let me know that the student needs a visa before the material can be distributed. When we started the process to get the study visa, we found out that it will not be possible to obtain a visa by studying part time - she must be studying full time. I subsequently wanted to cancel the registration. I have sent two emails, requesting the cancellation, and the consultant is responding to the emails, but not letting me cancel the registration. I have phoned Intec trying to cancel the registration, to no avail. Sent a third email today with no response. I want someone that can help me cancel this registration.