They made my MyZone card LTF when I raised a closure request. When the retention team called, I told them clearly that the card was now LTF for new customers, and there was no way I was going to pay for it.
I made my pre-approved MyZone card from paid to LTF with 15 days of card arrival, luckily I got a decent limit of 1 lakh. So, I will recommend you to try one or two times again rather than closing and applying again.