Is this a legal repossession?

The furniture store is obligated to honor the contract that you signed when you agreed to buy the furniture.  if you have a contract where you are on a payment plan and you have not missed any payments, then the furniture company may not accelerate their right to collect the full balance of the payment.  In other words, you contracted to make monthly payments until the furniture was paid in full.  as long as you are paying, the company cannot repo the furniture.  i suggest that you review your payment records to confirm you are on schedule and have not missed the payments.  if you did miss a payment, then the company can sue you for the balance owed or repo the furniture.  you need to meet with a lawyer to review the documents to determine whether you are exposed to liability.