Damaged items, no refund.

I purchased a Fitbit on takealot recently. After wearing my Fitbit in the gym (where it’s supposed to be worn) somehow, during my workout I must have bumped the screen on something and it cracked!!! So I sent y back in, to which they told me they cannot replaced or fix it as the Fitbit Warrenty is void if any screen damage is visible!!!! Okay, fair enough.... So they send it back to me. The problem, now it doesn’t work at all!!!! When I sent it in, all that was wrong was the little crack. Now I cannot even use my device because the takealot team have totally ruined it!!!!!! This is unacceptable, I paid R3000 for this device and now I cannot even use it? Please sort this out takealot.....