Why is my cat acting like this?

About one day ago my mum decided to adopt a cat from a friends friend , this cat is a white/silver Persian chinchilla about to turn 5 and about 1k in Australia. It has been vaccinated, toilet trained, micro chipped and has received worm treatment. Yesterday my family of 3 (including myself) gave it a lot of attention because we just adore the cat, everything was fine, it was acting expectantly curious and exploratory but the next day, I think I got on its nerve but stroking its tail , it's next grooming is due and I may have tugged on it's knot. Now it's ignoring me and ignoring any gestures I do , to try and get it to come near me , help me please ?