Shoppers Drug Mart review: gift card

I bought a gift card for Best Buy on Jun 13, 2019. Two days later, I went to Best Buy and tried to use it to purchase a tv. The gift card didn't work. The cashier told me he couldn't check the balance, and the system said only "Declined".
I went back to Shoppers, and they gave me a number to call. I called the number, and opened a case. I sent the receipt and all pictures they requested.
On July 4 they sent me an email informing me that the issue had been escalated to Black Hawk.
On July 12 they sent another email confirming that the problem was with the manufacturer, and offered me a $100 Shoppers gift card to settle the issue.
I replied on the same day saying this was NOT acceptable. I cannot use a shoppers gift card to make a purchase at best buy. I paid for the gift card with my visa, so I want the money back on my visa. Or they could send me a cheque to my home address.
After this, they stopped replying and I haven't heard back ever since.