... as Penny mentioned, u must have a return flight ticket if u arrived on a visitor's visa.
... and I assume that the 20th June is the return date ?
Would it not be best to contact the relevant airline company & see if u can advance the
flight to a much, much earlier date ?
If there is a penalty fee, surely it's in BOTH of your interests that he pays the difference,
and at least helps you to get home earlier.
... and I'm sorry for you that this situation has arisen.