I have never seen such irresponsible seller before who keeps on pushing away his responsibility to so-called different persona in the same account.

As far as I concerned:
1. buyer shall have the right to sue for damages for non-delivery from the seller's negligence. [s.57 of sale of goods act]
2. seller is bound to deliver the product in accordance to the terms of sale. (to deliver on or before 25/4/16) [s.33]

Clearly, the seller had breached the contract of sale.

Just bring this case to the police or the court. Exercise your rights as a consumer.