Swiggy — no response for an issue of changing my phone number

Address:

Bangalore, Karnataka, 560037

I tried to change my old phone number to a new number as the previous one is no longer valid. I tried through the app but everytime I entered the OTP, it said - "the OTP has expired." When I tried on their website it said the same thing. Later when I tried again, it said- "Maximum tries for mobile number change exceeded. Please contact customer care." So I called the customer care. But it was of no use as in Swiggy, our call is attended only if we call with our registered phone number. In my case my old number is no more valid. So, I tweeted them at @SwiggyCares 5 days ago. As I received no reply, I tweeted them again to deactivate my account. I mailed them too. I tried to leave a feedback on their site but it threw some errors. It is a shame that they are losing out of dedicated customers like this. If they can't handle a small technical issue, I wonder if they are going to trend.

Now, I have no idea as to how to deactivate my account.