Enrolments only for limited duration

Content

Employees can avail loan ranging anywhere between $50 and $500. Lets say the employee avails $120.
The company gets the loan for employee and the same amount would be deducted from employee's salary over 12 months i.e. $10 in this case.
The employee cannot avail this until all the amount is recovered.

The employee can avail further loan if the person wishes after 12 months.

Benefit plan:
1) Create a unrestricted benefit plan called "Employee Loan".
2) Create Rate for the plan with calculation Method as "Flat amount" and "Participants enter value during enrollment"

Minimum Election Value 50
Increment 1
Maximum Election Value 500
Default Value 0

3) I send monthly amount to payroll via an element entry.