Substandard Product refuse refund

I purchased a insulated bottle through takealot and paud R275. After 1 month the very flimsy cap strap broke off. I send it back for replacement/refund. They informed my they cant as it was due to misuse. I corresponded with them sending reviews from other customers complaining about the same problem. I was informed that they will take it up with the company who made it..... next moment I receive it back (the broken one) This is due to substandard pro**** not misuse. I have had plenty of the same kind of bottles and never had anything brake on it. Now they are ignoring me.