Vueling has abhorrent customer service, in my experience.

I filed a compensation claim wrt EC261; during the entire seven months it took to get compensation, not ONE time did anyone from Vueling respond.

However, I did I a couple of things to get it all sorted.
1) recorded the captain -- in Spanish and English -- mentioning the reason for the delay. That was lucky. Transcribed it, then attached it as a .doc to the insurance company.
2) Wrote to an ombudsman.