Not claimed 50% presumptive deduction under 194 JB for the last 20 years-excess I T Paid-

Dear Sirs

For the last 20 years, I have been teaching as a Visiting Faculty for Finance.  Colleges have deducted  10 %TDS under Section 194 JB.

I was not aware that I could claim 50% as presumptive expenditure out of my total income.  I have shown 100% Income, as taxable income and have paid tax for the last 20 years.  In fact, I have incurred a lot of expenditure, as Taxi Fare, and Driver and Petrol charges, whenever I have traveled in my own Car.  Incurred other expenditure also for reading material, internet charges etc.   Is there any provision, under Income Tax rules, to make a special appeal to claim a refund for the last 10 years at least, as the mistake is genuine, and excess tax paid on 50% on professional income earned as a Visiting Faculty?    I can not understand How the I T Returns were assessed, when TDS was shown under Sec.194 JB and my Income was taken 100%, without claiming eligible deduction.  I will be grateful for the guidance to prepare an appeal to the I T Department.    yours sincerely.   G V Subba Rao.  Visiting Professor.  9326189241,   raobob07 @ gmailo.com.   Pune.