Touchscreen troubles

I recently had my screen replaced on my I phone 5c from a vender in our local mall. The screen had been previously cracked for about 6 mnths and functioned fine until I dropped the phone after being outside in freezing weather for a few hours. At any rate now it is acting all hay wire like my touch screen doesn't always work properly... I press one thing I get another... Especially if the phone is cold or my hands are hot then the touch screen doesn't work at all... My question is should I be heading back to the mall and asking some questions about my repair? I was reading previous post on calibrating touch screen and I tried a couple ideas... It mentioned something about it being in the front panel which I just had replaced so I'm wondering if I got a faulty repair or if it's something else entirely?