Telkom Bayside very bad service

Telkom service is very bad, I opened a contract yesterday at Table view bay side telkom store. The contract was for 24 months Samsung s21+, I gave it a try during the evening and noticed that the battery is very bad, I went online and do some research and noticed that s21+ battery is not good

I then went to the store in the morning to cancel the contract so that they can take their device and cancel the contract,

They gave me tough time saying I can't cancel the contract, I asked if they can at least give me iPhone and they mentioned that they cannot issue a different device either because I received it from the store.

I asked a question that they must show me where it's written on the contract that I have signed that I can't return and cancel the contract and they couldnt point it to me any where on the contract.

I really feel like this is a ******* because most contracts are cancellable within 7 days, but not with telkom.

It's like they don't trust this devices which is why they never want them back. I didn't expect such service from Telkom because the device still have all the stickers only the box was opened on store. Now I just have to suffer for 24 months with the device I'm not happy with, Because now with Corona virus we can't even browse the devices to see how they behave