Samsung Z4 OS Tizen

Good day

I purchased a Samsung Z4 handset from Edgars Active less than ONE WEEK ago. Once i started using it i only then realised that the phone wasnt using the ANDROID OS but SAMSUNG's Own called "tizen". Im truly dissapointed in the phone. I cant even download or install proper apps like one does with the Android OS. There isnt even a clear indication that the phone uses another OS other than Android. I keep getting errors when installing apps like whattsapp and facebook and Yes i did reset my phone once already and still the same error. Is there a way to return this handset since its within the 7 day "warranty"? if NOT how will this issie be resolved.

thank you