Battery faulty

I bought a li-ion battery from Knysna Battery Center on 2025-03-25. The battery was installed in a complex swing gate motor. On 2025-04-07 the battery was completely flat. 5V when tested. I took it back and asked for it to be replaced or refunded. I was told it must be send to PE for testing. i bought a lead acid battery because the li-ion was out of stock and the security gate had to be in working order. On 2025-04-23 i enquired wat is going on. I was informed the battery is still in PE. On 2025-04-30 i was informed the battery is back charged. I informed the sales person i would like a refund because i do not need the faulty battery anymore. I will not be able to use this battery for client knowing it is faulty. I am an gate motor installer and proud of my work but can not say the same of this business.