Monitor color problem? plz plz hlp!?

Yesterday I sent my LG CRT monitor (Came with MG MyPC Computer) to a service shop for changing damaged (cut by Rats) signal cable. During coming to home monitor suddenly fell down on road. now, the problem is that it is showing incorrect colors (colored spots) on screen. what may be problem? Is this damage due to fall-down OR did the repair-man messed up (changed something inside) with it? How much will it cost to repair this problem? Is picture-tube damaged OR something else. plz hlp.