How to fix LCD Screen and Black line?

I have a problem with my iphone 3gs, i dropped it a month ago, and a small crack appeared below the glass and what appears to be on the LCD screen. I am in South Africa, and was in Cape Town at the time so enquired on cost and a friend said he could get it replaced for me for R350, which is a good deal. However I then had to come back up to Johannesburg, and havent been able to find someone who will do it for the same price. Yesterday, I was sitting at my desk, with my phone next to me, and two lines appeared on my screen adjacent to the crack, they were small, and crossed over half of the screen horizontally. I then went to bed last night and woke up to the cracks extending from end to end of the screen horizontally. Is this damage caused by the crack? If I replace the LCD screen will the black lines go away too?

My phone is hacked so that I can use it in South Africa, so cannot take it into an Apple store...