Refusal to accept different proof of purchase

Dear Sir / Madam

I purchased a Hisense cell phone at Pepcell Maponya mall in February 2021 unfortunately I misplaced the slip. I however still have the box.

The battery does not last for even two hours. The sales assistant refused to take a phone for repairs because I lost the slip.

I Used my bank card to pay for the phone and the payment is reflected on my bank statement. The sales assistant I spoke to was Boipelo Mokone. I don't understand why that cannot be accepted as proof of purchase.

I'm very disappointed with the lifespan of this battery as the phone is only three months old.

I will appreciate your assistance is this matter.

Kind regards Pamela Maphalala ***