Toothsi — Stopped responding after payment for full plan

Initially they were all super responsive. I paid 52000 for my plan and had to submit my X-rays and other documents. When I did, the orthodontist said the alignment of the underbite isn’t possible with aligners. So they said we’ll upgrade you to prime plan free of cost. I was asked to send another gum assessment document, after which they stopped responding to my calls. I tried reaching out 7/8 times via chat and 3/4 times via call. Every single time they said they’d contact my person of contact to call me back and I didn’t receive the call from her till now. I wanted to seek refund and cancel the plan but they’ve stopped responding.