HSA doesn't refund employees negative amounts but uses them in the calculations

Summary:

If an employee has an initial HSA election then has a life event and changes the HSA election to less than what has already been taken out it doesn't take out the negative amount however, if the employee has another life event and annual election is now higher than what they have contributed it accounts for what it thinks was refunded. Benefit administrators know not to put an annual amount less than what has been taken out but we have this as a self-service event as well and employees are confused.

Ex:

Initial HSA election $3600 and a total of $900 was taken out before the next life event