Hi. I suspect that the ‘send money’ option should have a ‘block sender’ feature to prevent misuse by disgruntled ex-partners (or anyone else who is trying to intimatate or annoy a person).
There have been cases of this sort of thing in the USA and I think they are bad publicity for the services involved.
I think that the rule should be “don’t create an instant messenger service where the receiver cannot create a blacklist”