The most reliable way to "swap" your retail card for a prepaid one is through a secondary marketplace. You sell your unwanted card for cash, then use that cash to buy a prepaid card.
: Known for high payout rates (up to 93% for in-demand brands like Amazon or Target), this site is ideal if you want to maximize the return on your original card. 2. The "Amazon Hack" for Small Balances
Load it into your account. While this doesn't give you a "prepaid card," it consolidates multiple balances into one usable balance for any purchase. 3. In-Person Exchange Kiosks