Vueling Change flights but will only refund cost of 1 leg.

I cannot believe how badly I an being treated by Vueling. I booked flights from Malaga to Malta leaving Malaga early 18 October for a 7 night holiday returning 25 October. Yesterday I recieved an email from them saying they had changed my flight times, not only did this now involve a 10 hour tranfer time in Barcelona but also it is 2 days later. I asked what I believe is reasonable and that is to change the return flight to the 27 October so I can still have a 7 day holiday. Back came the reply that I can only get free changes or a refund to the re-scheduled flight not for the return flight if I want to fly 27th instead of 25th it will cost 39€ per person to change. What makes this more annoying is that the flights on 27th October are about 50% less than the 25th. I now do not know what to do I have already lost money on a hotel I have booked for the night before when we should have flown.
This is what they say
Thank you for contacting Vueling. In response to your e-mail we would like to indicate that we have checked your reservation and, as your outgoing flight was changed from October the 18th to October the 20th, we could refund you this leg of the travel, but not the whole reservation.