I did an international transfer via my bank for �1800. My bank lost the transfer and after a few days although?

I think that it is 90% your fault for not knowing the amount available in your account. I have had a Bank account for 50 years, and always know approximately how much is available, before spending. You have had �30 compensation, so you cannot really expect much else from them, but you can talk to them to try to resolve your predicament.