e-currency sounds lame... how about just.. currency?
Ok let me rephrase that, if a bank decides to reverse the payment in claim of you selling ecurrencies can you take them to court and hope to hold them accountable of paying you the damages not taking into account the likeliness of the ignorance of the judge about the technical aspect and the probability of him raising an eyebrow?
If you are asking from a legal perspective, then that's different. It would depend on your own governing laws and any existing precedents..
Only a court could probably give you a truly definitive answer here.
In most jurisdictions, cryptocurrencies are a grey area, because its still so early in the whole picture.
Many crypto-centered cases are a first of their kind so there isn't always a precedent to define it one way or another.
If buying and selling cryptocurrencies is
not illegal where you are, then you
may have a case against the bank in this instance.
It would be best to find a lawyer that can advise you correctly, or at the very least, seek out Legal Aid to determine whether you have a case or not.
Is there even a legal definition for Bitcoin and cryptocurrencies where you are? You'd need to start here..