tier 2 Visa Extension refused due to error on salary

[mak7799]

Hi All

I need an urgent advice regarding my visa extension.

My tier 2 visa extension was due on 28 December 2015. I applied for extension before the expiry but made a mistake about the salary and didn't realise it until recieved a refusal letter on 14th Jan 2016.
I applied for a administrative review with a letter from employer about the mistake however it was unsuccefull and recieved the response on Thursday.

also my 10 year in the UK will be completed in August 2016

Now my questions are;

can i make a fresh application under tier 2 with the correct information?

will this refusal have any ill affect on my 10 year continious stay?

have a still got 28 days grace period after the date of the refusal of admin review?

I thank you guys in advance for taking the time out for your reply.