WRONG UNITS

GOOD DAY I WENT TO VODASHOP RICHARDS BAY ON THE 14 JANUARY 2015 TO UPGRADE ONE OF MY ACCOUNTS, I WAS TOLD BY THE SALES LADY THAT THEY HAD AN APPLE AIR IN STOCK OR IF I WANT AN APPLE AIR 2 I CAN WAIT A FEW DAYS, I WAS MORE THAT WILLING TO TAKE THE APPLE AIR AND SIGNED MY CONTRACT AND LEFT MORE THAN A WEEK LATER I WAS CONTACTED BY THEM SAYING THAT THEY HAVE GIVEN ME AN AIR 2 INSTEAD OF AN AIR, NO WERE ON THE BOX NOR THE DEVICE DOES IT SAY IT IS AN APPLE 2 AND THEY COULD NOT TELL ME HOW I COULD FIND OUT, AFTER I CONTACTED APPLE DURBAN THEY HAVE TAKEN MY IMEI NR THEY HAVE TOLD ME THAT IT IS AN AIR 2, THE COMPANY HAS CHANGED MY CONTRACT FROM A 3G APPLE AIR THAT COST ME R399 TO AN 2G AIR 2 THAT COST ME R479 NOW, I DO NOT THINK THAT IS FAIR, BUT BESIDES THAT ON SATURDAY THE 31 JANUARY WHEN I CHECKED MY BALANCE FOR MY DATA ON MY DEVICE MY DATA WAS GONE AS WELL AND THERE WERE MORE THAT 5G LEFT THE NIGHT BEFORE, I HAVE CONTACTED THEM AND STILL WAITING FOR THERE REPLY, I JUST FEEL HOW CAN THEY TAKE SOMETHING AWAY THAT I PAID FOR. THIS DID NOT JUST HAPPEND TO ME IT HAPPEND TO MY FRIEND ASWELL BY THE SAME COMPANY 2 DAYS LATER. I JUST FEEL ITS NOT FAIR