Travelstart wants the OTP from the bank?????

I have booked a ticket on the 17th Oct and then received notification that only R300 was deducted from my account iso R2700. I received an OTP again as well as a message from ABSA warning me to never give the OTP to anyone. Then a lady from "Travelstart" called me to ask for the new OTP?? She said that the full amount did not go off and that she needs the new OTP to complete my booking. ??? I was suspicious immediately and questioned her . She could not explain exactly why she needs the OTP, she kept on saying that the full amount did not go off. I then said this is a **** whereupon she told me that she will send me a link and then I have to add my card details in the link and she will then be able to complete the booking???? This must ne a ****! - I asked her to cancel my booking and repay the R300. She confirmed that it will be done?. I called Travelstart to alert them to the possibility of a **** being run under their name and, unbelievable but true, the agent I spoke to said this is how they do business?????? More than 1 amount is being deducted and the bank then does not honor the 2nd deduction. That is why they need the OTP? I want to warn everyone about this ! Has anyone experienced the same where the OTP is needed by the company ?? This leaves you as consumer very vulnerable and any amount can be deducted from your account???? Can this be a ****???