India Rehab Centre — they call for donation and if you deny they are very rude to you

Address:	New Delhi, Delhi
Website:	www.indiarehabcentre.org

Hi,

I keep getting call saying that we are calling from india rehab centre and one kid needs your help etc. Once i gave rs 1000/- but was not given any receipt or feedback etc. After which i decided that i will not give them any money and will donate only to genuine ngos like cry etc.

After one month got again a call from them, but i disconnected. Soon after i got a call back from same person and this time his tone and tenure was different. He started shouting at me saying how dare you cut the call. This was very surprising to me and we had some heated argument and after that i blocked him.

Again in a months time, i get another call naming same organisation, this time i told them "i am not interested please don't call", to which the caller replied back "what should we do so that you are interested, should we ask that child to dance in front of you" i blocked as i knew scolding them will only waste my time.
But my question is i now know that they are fraud or if they are not how they are able to talk to me like that as if i am obliged to give them money.

Here is the website, kindly let me know if you have faced similar trauma through them and how this can be taken up legally against this organization

https://www.indiarehabcentre.org/case.php