Prior to or after any action by the seller or his agents to repossess consumer goods under the terms of any such conditional sales contract or contracts involving both previous and subsequent purchases which have not been fully paid, the seller must retroactively allocate all payments received under the contract or contracts to the various purchases in the same proportion or ratio as the original cash prices of the various purchases bear to one another. However, the amount of initial or down payment involved in each purchase shall be allocated in its entirety to such purchase. The result of such allocation shall be reported to the buyer who has the right to complete payment on any of the purchases consolidated in the conditional sales contract within 15 days from receipt of the allocation report from the seller. Any purchases upon which the payments have been so completed are exempt from repossession by the seller. Provisions of this section do not apply to sales involving equipment, parts, or other merchandise attached or affixed to goods previously purchased or repairs or services rendered by the seller in connection therewith at the buyer’s request.