Bad experience after buying

I went to Pretoria North branch and I bought a vehicle there and I now have financial situation, I then called dealer and asked if I can downgrade as I don't I can afford the installment .They told me its not possible.<br> I called their head office they said its possible and referred me to Regional manager Manas Scolt who then referred me to Coreen and confirmed its not possible.<br> <br> I fail to believe this as am still within 7days of purchase. Can somebody help please.<br> I AM NOT CANCELLING , I JUST WANT TO DOWNGRADE<br> <br>