As far as i know, it may please be noted, 4 years and 240 days or 8 months is enough to qualify for gratuity amount. However, the 5 year it will be paid on pro-rata as the year is not complete.
Hope this clarifies. Please write in an email /letter to them in 1st instance, follow up. Else , you can approach concerned HR department seek clarification. Else, you can approach labour court and seek their intervention with your case.
However, kindly note, there is no break in service in between the period.
Please go through the following paras to get a better understanding in case you have not yet done it.
Payment of Gratuity.- (1) Gratuity shall be payable to an employee on the termination of his employment after he has rendered continuous service for not less than five years,-
(a) on his superannuation, or
(b) on his retirement or resignation,
(c) on his death or disablement due to accident or disease:
Provided that the completion of continuous service of five years shall not be
necessary where the termination of the employment of any employee is due to
death or disablement.
For the said period of one year, if the employee during the period of twelve calendar months preceding the date with reference to which calculation is to be made, has actually worked under the employer for not less than-
(i) one hundred and ninety days, in the case of an employee employed below the ground in a mine or in an establishment which works for less than six days in a week; and
(ii) two hundred and forty days, in any other case.
Yours is a borderline case but not legally bound to pay as you have not fulfilled the clause (ii) stated above- 240 days in the fifth year, as rightly mentioned by Mr Nathrao
Thanks and Regards