To see improvement you must have to  use insoles for flat feet and then work on strengthening exercises for foot muscles.. Improvement is depend how severe flat feet is no.. You can video consultation to get to know

If it is an Acquired adult flat foot there are possibilities of correction. You should do ankle and foot strengthening exercises with proper guidance. You should do calf muscles stretching and strengthening exercises with guidance. You can use ankle foot orthosis.

1st of all, flat foot can not be ocuure suddenly as u said in 2013. U have to tell what kind of treatments or modification u hv done till now. Detail assessment of foot in weight bearing and non weight bearing position is required. Yes proper corrective and strengthening exercises can definately help you along with shoe correction..

Before answering I want to know how become in 2013 you have diagnosed with flat foot , is there any past history pls explain

Start using insole . Change your foot wear. Start doing exercises for foot like Strengthening and stretching. Towel curling exs and ball rolling under feet. Try to do heel raise and calf stretching 10 rep with the hold count20.

Yes things can be changed upto a certain extent based on whether that is a flexible or rigid flat feet. Kindly get a thorough assessment done followed by following a proper, comprehensive treatment plan for your condition.