I quit my job, tax rebate ?

Are you signing on for any benefits?

It's a little tricky to say without knowing how much you have actually earned.

But if you on the standard emergency tax code of 1185L on a cumulative basis and have earned say £17,318 so far this tax year (up to 5 November 2018, the end of month 7 of the tax year) then you might be due about £985 back if you no further taxable income in this tax year.

The actual figure will depend on your actual taxable income, which country you are resident in for tax purposes and possibly other things (do you owe tax for an earlier year or have any extra allowances included in your tax code?)

So if we assume that,

a) you don't have any more taxable income in this tax year
b) your tax code has been increased to from 1185L to 1199L due to you claiming flat rate expenses (laundry, tools etc)
c) you don't become Scottish resident for tax purposes

Then the tax you will owe for 2018:19 will be £1082 (£17,400 - £11,850 - £140 = £5410 x 20%).

You have already paid £2080 so should get a refund of £998.

Google gov.uk P50.

Well let HMRC know and they will remove the £140 and you'll get a slightly lower refund of £970 (less anything they say you owe for any earlier years you have received the additional £140 for)