thank you wasnt sure where to put it

hi all new here so any help will be greatly appreciated.i started for a comapny in july 2013 and worked until july 1st 2014 - i was made permanent from 1st january 2014 and was on £16,000 per annumi still keep in touch with friends from their and have heard that they have just been told that they have been given a pay rise to £18775 and it has been back dated to january 2014.i am obviously no longer with the company but having worked from january 1st until july 1st 2014 am i legally enititled to a back dated pay rise for this period.kind regards