Not helpful or contactable

My flight was changed unexpectedly by the airline, resulting in my trip being cut in half. I have been in contact with the airline and they informed me that if I still need to fly on the original date booked, they can transfer my flight to another airline they have an agreement with at no extra charge. I said I would like this and they informed me that I would need to contact budgetary.com to do this for me as they had booked the flight, but it is possible. I have now been told firstly it wasn't possible. And then three times that their colleagues who are specialised in these matter will take over and contact me via email. I have not received any further assistance from budgetary.com and keep receiving the same response when talking to the client service online.