ethiopian airlines poor attitude - check in on line unavailable - poor service award

Flight ET848 from JHB to Addis Ababa / Tel Aviv - Reserved seats, couldn’t check in beforehand online ? restricted?- got there three hours before, changed plane type and seats were changed ??, separated family members - a child - and an adult travelling together :( Unacceptable - policy is to keep family members together - the lady at check in was an unhelpful and downright rude. i am a loyalty club member and i travel 4 x a year !!!! this is the worst service i have ever received.