What does this mean please dont use google translate actually know Japanese?

...だて てないよ！: だて can mean "but..." and in this case "てない" is a form of denial a action. "よ" strengthens the denial. So the best translation would be: "Don't but me!"

じょうずだよ : (じょうず) is an adjective that means someone is skilled at doing something /// だよ - だ is kinda like "desu" and "yo" come to play to reinforce the idea so the meaning should be "He/she is skilled!".

So I think someone said "something something something but..." and the reply was "Don't but me! He/She is skilled"