Unfair treatment from vodacom

I'm very disappointed by the conduct of vodacom because now I'm being treated unfairly because I raised my concern and refused to take a contract that I was not happy of. I recently returned a laptop and cancelled a contract because the person that was assisting me **** and sold me something that wasn't correct. So now when I apply for the laptop I'm looking for online my request is being rejected we no valid reason, I feel like I wasn't even suppose to renew my other contract with vodacom and go and look for services somewhere else.