If I have a signed severance agreement stating that I am receiving 15 weeks pay and benefits and the $$ will be paid out in bi-weekly installments until paid in full, and then after a few paychecks, they pay the balance out in a lump sum (effectively canc

The signed separation letter states 15 weeks pay, another e-mail from the VP of Human Resources (who write the separation letter) states benefits are part of the severance. Letter says the sum total will be paid out in bi-weekly installments less lawful deductions until paid in full, which would carry my family on benefits through June. After three bi-weekly installments, they have made a very large lump deposit, and have not responded to my questions or explanations about it, nor have sent me any pay stubs. They have also locked me out of the online system to see the paystub there. I cannot understand this payment, but am wondering if they are violated the terms of the agreement. If so, do I have any recourse?