Down payments in retail stores

Hello expats,

I'm new here and first post, first question already. It's a bit of a general legal one.

My girlfriend and I are about to move into a new flat in Nairobi. She is Kenyan, I'm a mzungu

She wanted to purchase a sofa a few weeks ago at Nakumatt but was told they have up to 4 weeks delivery time. So she agreed to make a down payment of 40% and the rest at delivery. They gave her a manually written receipt (with Nakumatt logo and date stamp on it) because apparently their IT system was out of order. Fortunately she paid with her Visa card so she has an electronic transaction as evidence.

No sofa yet to be seen but now the furniture manager claims that the sofa was delivered which it wasn't. They "cannot find it". They refuse to reimburse her payment, under weird excuses that the receipt looks fake. They neither delivered the sofa nor want to pay back the down payment. The delivery done story wouldn't make sense anyway as she never paid the balance. They offered her a gift voucher lol

Any hint on what the legalities are of this kind of transaction would be appreciated. I know the popular shrug "well, this is Africa, sorry mate" but this is Nakumatt, not some flying dealer. This would punch a big hole into our budget if we don't get it back.

My girlfriend is a long time Nakumatt customer. It's very disappointing.

Thanks a lot for any help.
F

Edit: shouldn't it be possible to just contact the bank and post the Visa transaction back to her account, as a cancellation?