Thank you very much for clarifying. First of all, I am sorry to hear about the issues you have experienced in your situation.
Due to a significant increase in bank transfer fraud, a voluntary code was introduced in 2019 to provide consumers with some protection in the event they fell victims to such scams.
The Authorised Push Payment Contingent Reimbursement Model Voluntary Code offers such protection in the event the victims have met the standards described in the Code, when they fell for these scams.
The presumption in the Code is that victims of bank transfer fraud should be reimbursed unless there are clear grounds for attributing blame to the consumer. In general, anyone who has taken reasonable care when making such payments is likely to receive a refund of the lost money, whereas a victim who has been "grossly negligent" will not be reimbursed.
You can read more on how each bank may deal with this scenario here:
If you rare unhappy with their decision, you can consider taking this to the Financial Ombudsman for independent resolution. However, they are extremely busy at present – I had a claim with them which took nearly a year to resolve, but you could try them anyway, at least to have something done about it.