Groundhostess unprofessional/despicable behaviour

I travel with a Greek passport to Europe & UK. I have travelled twice to the UK with this passport (electronically chipped). Never before have i been denied access to boarding because there is no manual signature on the passport. The ground hostess refused to allow me to board unless I signed. When I asked her which signature (Greek or English) she was unable to tell me and said that my signature is my signature. I was concerned that any amendment on the passport would invalidate it but was willing to sign as long as she could assure me of this which she was unable to do and provided no guidance but rude and unhelpful behaviour. To the point where she was about to take my bag off the scale if I didn't sign in front of her. Apparently there are no supervisors either that could be called to assist me. I was therefore forced to sign to get onto the plain. The behaviour was despicable! I want to see how BA will address this and will contact the Greek Consulate re signature. FYI Leah Alberts (ground hostess who put me through this torture) didn't know that Greece was part of the EU and therefore did not require a VISA (clearly should not have her job or be client facing in any way).