is banning this champ bannabe

i was in a draft autofilled to support and was last ban this was while was free week who was 3rd pick was begging me to ban when i wanted to try support cause my only support was banned already which was banned by the player i ban so that the other team does not get her she was 4th pick overall and the likelihood of her getting her and doing well is very slim the player RAGES and when game starts starts to int cause they got and their was first pick and even said he was gona pick up if she was not banned

i ended up going support and almost won game with my adc

is what i did bannable?